Fix bugs in actions/install mixin

Extract installation tests in its own module
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