minor changes & bug fixes

Changelog :

• adds the License to the module files (#14 and #15), thx @fabaff for the contribution.
• Fixes some alerts from LGTM regarding exception handling (commit e970d36)
• adds the __version__ variable so it can be queried directly from the interpreter (0808deb)

fix for buggy 1.5.1

This fixes home-assistant/core#43568 by merging #13.

Version bumped to 1.5.1

first automated release to pypi

v1.5

bump to 1.5