title: Groovy get variables from file. variable=value
body: <p>Seems like this question for most of others looks too simple.
  I need a help with following problem.
  Has file(p.envs) with set of variables and values like:</p>
  
  <pre><code>VARIABLE=foo
  NOW=19 October 2014
  </code></pre>
  
  <p>How to read this file with Groovy to get an output like:</p>
  
  <pre><code>    new File('p.envs').eachLine { line -&gt;
         println line
         ...
      }
      ...
      println "NOW=$NOW"
      println "$NOW"
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>NOW=19 October 2014
  19 October 2014
  </code></pre>
  
  <p>This issue can help someone to inject custom variables to groovy template in Editable Email Notification Plugin in Jenkins.
  Thanks!</p>