Added missing exception class.
Merge pull request #5 from tjlytle/master

Added missing exception class.
Merge branch 'hotfix/5'

Close #5
Updated composer.json

- Added branch-alias of master to 1.0-dev
- Use ~ operator and "-dev" stability for deps
  - Add in some sub-dependencies so that we can remove the minimum-stability
    flag
Up minimum PHP version to 5.4.8
Relocated Module classfile to top-level directory
Merge branch 'hotfix/module-relocation'
Merge remote-tracking branch 'upstream/master' into links-as-resource-properties
Unit test for resource properties as links