grunt-bower-task failing testcase Fails to copy modules from a Git repository with no bower package file.

.bowerrc

{
    "directory": "app/lib"
}

bower.json

{
  "name": "testcase",
  "dependencies": {
    "Overthrow": "git://github.com/filamentgroup/Overthrow.git"
  }
}

Gruntfile.coffee

module.exports = (grunt) ->

 require("matchdep").filter("grunt-*")
  .forEach grunt.loadNpmTasks

 grunt.initConfig
  bower:
   install:
    options:
     targetDir: './app/lib'
     verbose: true
     install: true
     cleanup: true


 grunt.registerTask "build", [
  "bower:install"
 ]

 grunt.registerTask "default", ["build"]

package.json

{
  "name": "shopland",
  "version": "5.0.0",
  "engines": {
    "node": ">=0.8.0"
  },
  "dependencies": {
    "grunt-bower-task": "0.2.3",
    "grunt": "~0.4.1",
    "matchdep": "~0.1.2"
  }
}