title: Error when configuring frontend-maven-plugin : Try to 'execute npm run load' script
body: <p>When trying to configure frontend-maven-plugin for angular 4 project 
  the plugin is trying to execete a script called load ("npm run load") which is absent from the package.json.
  when adding the script, the build passes successfully.
  Is there a way to tell the plugin to not run this script?</p>
  
  <p>This is my package.json file</p>
  
  <pre><code>{
    "name": "historage-ui",
    "version": "1.0.0-SNAPSHOT",
    "license": "MIT",
    "scripts": {
      "ng": "ng",
      "start": "ng serve",
      "build": "ng build",
      "test": "ng test",
      "lint": "ng lint",
      "e2e": "ng e2e"
    },
    "private": true,
    "dependencies": {
      "@angular/animations": "^4.0.0",
      "@angular/common": "^4.0.0",
      "@angular/compiler": "^4.0.0",
      "@angular/core": "^4.0.0",
      "@angular/forms": "^4.0.0",
      "@angular/http": "^4.0.0",
      "@angular/platform-browser": "^4.0.0",
      "@angular/platform-browser-dynamic": "^4.0.0",
      "@angular/router": "^4.0.0",
      "core-js": "^2.4.1",
      "rxjs": "^5.1.0",
      "zone.js": "^0.8.4"
    },
    "devDependencies": {
      "@angular/cli": "1.1.3",
      "@angular/compiler-cli": "^4.0.0",
      "@angular/language-service": "^4.0.0",
      "@types/jasmine": "2.5.45",
      "@types/node": "~6.0.60",
      "codelyzer": "~3.0.1",
      "jasmine-core": "~2.6.2",
      "jasmine-spec-reporter": "~4.1.0",
      "karma": "~1.7.0",
      "karma-chrome-launcher": "~2.1.1",
      "karma-cli": "~1.0.1",
      "karma-coverage-istanbul-reporter": "^1.2.1",
      "karma-jasmine": "~1.1.0",
      "karma-jasmine-html-reporter": "^0.2.2",
      "protractor": "~5.1.2",
      "ts-node": "~3.0.4",
      "tslint": "~5.3.2",
      "typescript": "~2.3.3"
    }
  }
  </code></pre>
  
  <p>and this is the plugin configuration :</p>
  
  <pre><code>  &lt;plugin&gt;
          &lt;groupId&gt;com.github.eirslett&lt;/groupId&gt;
          &lt;artifactId&gt;frontend-maven-plugin&lt;/artifactId&gt;
          &lt;!-- optional --&gt;
          &lt;configuration&gt;
            &lt;workingDirectory&gt;src/main/historage-ui&lt;/workingDirectory&gt;
          &lt;/configuration&gt;
          &lt;executions&gt;
            &lt;execution&gt;
              &lt;id&gt;npm install&lt;/id&gt;
              &lt;goals&gt;
                &lt;goal&gt;npm&lt;/goal&gt;
              &lt;/goals&gt;
  
              &lt;!-- optional: default phase is "generate-resources" --&gt;
              &lt;phase&gt;generate-resources&lt;/phase&gt;
  
              &lt;configuration&gt;
                &lt;!-- optional: The default argument is actually
                "install", so unless you need to run some other npm command,
                you can remove this whole &lt;configuration&gt; section.
                --&gt;
                &lt;arguments&gt;install&lt;/arguments&gt;
              &lt;/configuration&gt;
            &lt;/execution&gt;
          &lt;/executions&gt;
        &lt;/plugin&gt;
  </code></pre>
  
  <p>This is the stack trace :
  [ERROR] Failed to execute goal com.github.eirslett:frontend-maven-plugin:1.0:npm (npm run load) on project historage_ui-js: Failed to run task: 'npm run load --proxy=htp://b77553:<strong><em>@10.255.123.73:8080' failed. (error code 1) -> [Help 1]
  org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal com.github.eirslett:frontend-maven-plugin:1.0:npm (npm run load) on project historage_ui-js: Failed to run task
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
      at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:108)
      at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:76)
      at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
      at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:116)
      at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:361)
      at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155)
      at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584)
      at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213)
      at org.apache.maven.cli.MavenCli.main(MavenCli.java:157)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
      at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
      at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
      at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
      at org.codehaus.classworlds.Launcher.main(Launcher.java:46)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
  Caused by: org.apache.maven.plugin.MojoFailureException: Failed to run task
      at com.github.eirslett.maven.plugins.frontend.mojo.AbstractFrontendMojo.execute(AbstractFrontendMojo.java:95)
      at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:133)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
      ... 25 more
  Caused by: com.github.eirslett.maven.plugins.frontend.lib.TaskRunnerException: 'npm run load --proxy=htp://b77553:</em></strong>@10.255.123.73:8080' failed. (error code 1)
      at com.github.eirslett.maven.plugins.frontend.lib.NodeTaskExecutor.execute(NodeTaskExecutor.java:60)
      at com.github.eirslett.maven.plugins.frontend.mojo.NpmMojo.execute(NpmMojo.java:62)
      at com.github.eirslett.maven.plugins.frontend.mojo.AbstractFrontendMojo.execute(AbstractFrontendMojo.java:89)</p>