Bump version

Require keras < 2.0.7 due to non-trivial API changes (keras-rl#134)

* Require keras < 2.0.7 due to non-trivial API changes

* Bump version

* Change URL

* Use pinned version for tests

* Attempt to make Travis happy

Prepare v0.3.0

Prepare new release

Prepare release

Prepare release

Various improvements for DQN, the replay memory, and CEM (keras-rl#31)

- Fix various problems with sequential memory
- Fix various problems with CEMAgent
- Remove duplicate forward pass from DQN agent
- Remove performance bottleneck from TrainIntervalLogger
- Add tests for core and memory classes
- Add integration test for CEM