Refactored conflicter, added _ask() regression test
Merge pull request #216 from passy/collision-ask-test

Refactored conflicter, added _ask() regression test
Export invoke as single module
Fix waiter scoping reset
Replaced 'read' with high-level 'prompt' lib

/ref #199

This changes the prompt API slightly and adds the following features:

    - `grunt-init` style coloring
    - `default` can be a function (in preperation of "magic defaults")
    - if `default` is a boolean, it will display a 'y/n' prompt with proper
      validation
    - validations occurs after a value is entered and not after the whole wizard
      completed
Monkey-patch prompt to remove verbose error message
Merge pull request #213 from passy/new-prompt

Prompt: Replaced 'read' with high-level 'prompt' library
changelog: Added prompt change
Merge pull request #217 from passy/waiter-fix

Fix async waiter race condition
Removed legacy testing support

Fix #157
Replaced path.existsSync with fs.existsSync
Fixed prompt value handling (ref #213)
Fix tests on Windows
Remove color on prompt text

Fixes issues where questions are invisible when using Solarized Dark.
Use `dargs`

https://github.com/sindresorhus/dargs
actions.copy should work with one argument (source==dest, like in actions.directory)

So that this:
  this.copy('Procfile', 'Procfile');

Can be written like this:
  this.copy('Procfile');
Make spawnCommand and runInstall methods public
Merge pull request #223 from SBoudrias/patch-spawn

Make spawnCommand and runInstall methods public
Action tests: JS style
Extracted 'spawn_command' into its own action module