Error pushing standalone jar

I was trying to push https://github.com/cloudfoundry/java-test-applications/tree/master/java-main-application. It failed with the following error:
```
D, [2014-06-27T03:18:39.468728 #88] DEBUG -- /tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/buildpack.rb:47:in `rescue in drive_buildpack_with_logger': Exception #<TypeError: can't convert Array into String> backtrace:
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/container/container_utils.rb:51:in `initialize'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/container/container_utils.rb:51:in `new'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/container/container_utils.rb:51:in `libs'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/framework/framework_utils.rb:87:in `block in link_libs'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/framework/framework_utils.rb:86:in `each'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/framework/framework_utils.rb:86:in `link_libs'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/framework/spring_auto_reconfiguration.rb:60:in `compile'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/buildpack.rb:78:in `block in compile'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/buildpack.rb:78:in `each'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/buildpack.rb:78:in `compile'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/bin/compile:28:in `block in <main>'
/tmp/buildpacks/ibm-websphere-liberty-buildpack/lib/liberty_buildpack/buildpack.rb:44:in `drive_buildpack_with_logger'
```

Traced the problem down to a regex in framework_utils.rb where a capturing group is used. A capturing group result is an array, so the code was trying to add an array of array instead of a simple array with a string.