Merge pull request #6 from supersmile2009/master

Allow omnipay/tests v3. Improve travis build matrix.

Merge pull request #4 from digitickets/Adding-more-standard-methods

Add purchase, complete purchase and complete authorise methods

Merge pull request #1 from delatbabel/update-manual

Add docblocks, add scripts, add void and refund methods

Update .travis.yml

Remove purchase() method

Update dependencies