Add whippet.{json,lock} files

- Add Modules/Helpers/FileLocator
- Look for plugins or whippet.json files
- Add Modules/Helpers/Dependencies
- Add Modules/Helpers/WhippetLock
- Add Modules/Dependencies
- Pre-DRY tests
- Handle already-cloned repos
- Add fromString/fromFile static methods to WhippetLock
- Show useful output
- s/Dependencies/DependenciesInstaller/
- Move new classes out of Modules\Helpers
- Check the hash before installing
- Move some test helpers into a separate trait
- Output errors
- Add DependenciesUpdater
- Add update command
- Add paths to gitignore
- Add plugins to DependenciesInstall
- Add plugins to DependenciesUpdater
- Add dependencies migrate command
- mv WhippetLock Files/WhippetLock
- Move some functionality from DependenciesUpdate into WhippetLock
- Rename dependencies, and update FileLocator usage
    - Rename Dependencies* classes
    - Pass directory instead of FileLocator
- Add isErr check to Migration
- Update: test for failed git command
- FileLocator: update message
- s/FileLocator/DirectoryLocator/
- DirectoryLocator: Prevent bug with plugins directory
- migrate: Pretty-print whippet.json
- Pretty-print whippet.lock
- Do not bork on missing whippet.lock
- Dependencies: Ignore plugins file entirely
- Print sensible error if plugins file not found
- Add getNullFactory() to tests
- Move JSON parsing/file writing out of WhippetLock into abstract class
- Support explicit src
- Allow themes/plugins without refs
- Catch failing clones
- Catch failing checkouts
- fromString and fromFile return result objects
- Blank lockfile: show a message
- Blank json file: show message
- Tests: don't override that method
- Don't output warning on missing .gitignore
- Add Files/WhippetJson
- Handle removing previously-installed dependencies from gitignore
- Migration: do not overwrite existing whippet.json
- Fix a couple of bugs in Updater
    - Bubble errors properly
    - Don't bork if whippet.lock is missing
- Dependencies/Updater: refactor for readability
- Dependencies/Installer: refactor for readability
- Dependencies/Migration: refactor for readability
- Make deps an alias for dependencies
- Catch a broken JSON issue
- Add deprecation notice to plugins install/upgrade
- Update whippet_init to find whippet.json
- deploy: use Dependencies/Installer if possible
- Modify the deprecation notice for internal use of Module/Plugin
- Replace DirectoryLocator with ProjectDirectory
- Improve getFactory() test helper
- Do not directly instantiate other classes in tests
- Instantiate Installer correctly
- DRY
- Update README
- Lock sebastian/environment at a version that supports PHP 5.5

Fixes: #41

composer.json

@@ -4,12 +4,16 @@
     "minimum-stability": "dev",
     "require": {
         "dxw/rubbishthorclone": "dev-master",
-        "aura/autoload": "2.x-dev"
+        "aura/autoload": "2.x-dev",
+        "nikita2206/result": "dev-master",
+        "kevinlebrun/colors.php": "dev-master"
     },
     "bin": ["bin/whippet"],
     "require-dev": {
         "phpunit/phpunit": "4.8.*",
-        "dxw/phar-install": "dev-master"
+        "dxw/phar-install": "dev-master",
+        "mikey179/vfsStream": "~1.6@dev",
+        "sebastian/environment": "1.3.6"
     },
     "scripts": {
         "post-update-cmd": "vendor/bin/phar-install"