Start 0.5.0 development.
Fixes #19.

Added lifecycle hooks to DS.save and DS.create. #7
Closes #7.

Implemented all lifecycle hooks, including tests.

Cleaned up use of promises in async methods.
Merge pull request #20 from jmdobry/feature-lifecycle

feature-lifecycle
Finished integration tests for async methods. #15
Wrote several test for sync methods. #15
Finished integration tests.
Adapters now pluggable.

API needs work though.
Merge pull request #21 from jmdobry/0.5.0

0.5.0