Update phpunit, mockery and boris composer packages
Add a license file - MIT

Per discussion in GitHub issue #346, we're applying the MIT license
to the VVV project, copyright the contributors of the VVV project.
Make note of MIT license in the VVV Contributing document
Add copyright / license note to README
Merge pull request #431 from GaryJones/update-composer-packages

Update phpunit, mockery and boris composer packages
Merge pull request #453 from Varying-Vagrant-Vagrants/new/license

Apply the MIT License to VVV

So happy.

Fixes #346
Disable xdebug in provisioner and only enable it in our vagrant config.
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Add copyright / license note to README
  Make note of MIT license in the VVV Contributing document
  Add a license file - MIT
  Update phpunit, mockery and boris composer packages
Merge branch 'master' of github.com:morganestes/VVV

* 'master' of github.com:morganestes/VVV:
  Disable xdebug in provisioner and only enable it in our vagrant config.