title: SBT can't resolve dependency in build definition
body: <p>I'm making an SBT task that needs to make a multipart POST request to a certain server. I want to use Dispatch to make the request. I have the following in <code>build.sbt</code> at the top level of my project:</p>
  
  <pre><code>libraryDependencies ++= Seq(
    "net.databinder.dispatch" %% "dispatch-core" % "0.9.5"
  )
  </code></pre>
  
  <p>The task definition is in <code>project/Build.scala</code>. I have</p>
  
  <pre><code>import sbt._
  import Keys._
  import dispatch._
  
  object SubmitBuild extends Build {
    ...
  }
  </code></pre>
  
  <p>I get the following error message:</p>
  
  <pre><code>[error] /Users/ken/xxxxtools/project/Build.scala:3: not found: object dispatch
  [error] import dispatch._
  [error]        ^
  </code></pre>
  
  <p>If I remove <code>import dispatch._</code> then sbt will compile. I know I have Dispatch installed. Why can't SBT find it?</p>