Fix bugs in actions/install mixin

Extract installation tests in its own module
Added test comparing file modes after copying an executable file, relates to #464

Preserve file mode on actions.template, fixes #464
Merge pull request #474 from ruyadorno/iss-464

Added the ability to preserve file mode on method actions.template
Add defaults queue group and run common methods in them

Now Conflicter#resolve is only called once after all method ran
Now Base#installDependencies is called once at the end unless
--skip-install is passed as option. (This required some changes in test so
not every Generator test spawned an install process)
Link prototype method and hash to their queue
Merge pull request #475 from SBoudrias/group-queue

Grouped Queue
Add tests for the uncovered helpers methods
Fix style guide
Update gulp plugins and fix coverage reports
package.json: updating authors
Test coverage of the invoke method.
Replace throwing if statement with assertion
Merge pull request #480 from SBoudrias/assert

Replace throwing if statement with assertion
Merge pull request #479 from SBoudrias/invoke

Test coverage of the invoke method.
Update fetch.js

Go back to previous behavior, in order to have:
```
     info This might take a few moments
....
✔ Done in /home/jerome/.cache/yeoman/symfony/symfony-standard/v2.4.1
```
Merge pull request #482 from jdespatis/master

Fix #414
Use default values in mockPrompt
Merge pull request #487 from hurrymaplelad/mock_prompt_defaults

Add useDefaults option to mockPrompt
Update Gulp and fail build when jshint reports errors
Close GH-489: Added funtionality to change template delimiters in the template engine..