title: Custom build Type not working on androidTest building
body: <p>Hi i am trying to build a androidTest APK based on a flavour and a custom build type i have defined below:</p>
  
  <pre><code> productFlavors {
      FlavourOne {
          applicationIdSuffix ".live"
          buildConfigField 'String', 'SERVER_BASE_URL', '"http://live.com"'
  
      }
      FlavourTwo {
          applicationIdSuffix ".demo"
          buildConfigField 'String', 'SERVER_BASE_URL', '"http://demo.com"'
      }
  </code></pre>
  
  <p>}</p>
  
  <pre><code>buildTypes {
          debug {
              minifyEnabled false
              // shrink code (remove unused classes and methods) - note that it falls back to experimental shrinker for Instant Run
              shrinkResources false // don't strip unused res files
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro', 'proguard-rules-debug.pro'
              testProguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules-test.pro'
          }
          release {
              minifyEnabled true // shrink code (remove unused classes and methods)
              shrinkResources false // don't strip unused res files
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
              signingConfig signingConfigs.release
          }
          debugDemo {
              applicationIdSuffix '.demo'
              versionNameSuffix '-DEMO'
              minifyEnabled false
              // shrink code (remove unused classes and methods) - note that it falls back to experimental shrinker for Instant Run
              shrinkResources false // don't strip unused res files
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro', 'proguard-rules-debug.pro'
              testProguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules-test.pro'
          }
          demo {
              applicationIdSuffix '.demo'
              versionNameSuffix '-DEMO'
              minifyEnabled true // shrink code (remove unused classes and methods)
              shrinkResources false // don't strip unused res files
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
              signingConfig signingConfigs.release
          }
  </code></pre>
  
  <p>When i run <code>gradlew assembleFlavourOneDebugDemoAndroidTest</code>  i get an error straight away saying</p>
  
  <pre><code>Task 'assembleFlavourOneDebugDemoAndroidTest' not found in root project 'MyProject'.
  </code></pre>
  
  <p>It works fine if i omit my custom buildType and just do <code>assembleFlavourOneAndroidTest</code> and it works. It also works if do <code>assembleFlavourOneDebugANdroidTest</code> only...</p>