Ensure that Robolectric defaults to the targetSdkVersion specified in
the AndroidManifest if no @Config annotations are found.  Since the
@Config annotation had a default value for emulateSdk, the test runner
would always pick this version if no annotations were found.
Merge pull request #776 from erd/fix-test-runner-sdk-configuration

Ensure that Robolectric defaults to the targetSdkVersion specified in the manifest.