Release 0.7.0

Summary:
This feature release adds the ability to test structured facts, manifest
ordering, and trusted node facts, and check out branches with fixtures.

Features:
- Add `STRINGIFY_FACTS=no` for structured facts
- Add `TRUSTED_NODE_DATA=yes` for trusted node data
- Add `ORDERING=<order>` for manifest ordering
- Add `:branch` support for fixtures on a branch.

Bugfixes:
- Fix puppet-lint to ignore spec/fixtures/
Merge pull request #72 from hunner/release_0.7.0

Release 0.7.0