Bump the version to 1.3.1

Bump the version to 1.3.0

Bump the version to 1.2.2

Bump the version to 1.2.1

Merge pull request messagebird#13 from messagebird/lookup

Add support for the Lookup API

Bump the version to 1.1.1

Merge pull request messagebird#11 from messagebird/verify-api

Add support for the Verify API

Bump the version to 1.0.5

Fix typo in clientVersion parameter, bump version to 1.0.4

messagebird#5 Add to test that numeric senders will be prefixed with …

…'+' in the json result. (2)