Don't send sensor subscriptions async.

They're using a non-blocking send, so it's unnecessary to use a separate
GoRoutine. This was additionally causing the tests to occasionally fail
because the sensor was subscriped to before notifySubscribers had
executed for the initial setup.

Merge branch 'time_of_day'

Bump Go version to 1.7.4

Version 0.1.0

First commit.

Tag to allow `git describe` to work.