Merge branch 'release/v0.5.0' into develop

* release/v0.5.0:
  Updating description and branch aliases for composer
  Adding disclaimer and acknowledgements to README
  Bumped version to 0.5.0
Loosening version constraint on doctrine/collections
Bumped version to v0.5.1
Merge branch 'release/v0.5.1'

* release/v0.5.1:
  Bumped version to v0.5.1
  Loosening version constraint on doctrine/collections