chore(tests): Add a method to get number of times each message was sent over the mock desktop channel.
Merge pull request #836 from mozilla/mock-channel-test-cleanup

chore(tests): Add a method to get number of times each message was sent over the mock desktop channel.

Looks great @ckarlof, thanks for the cleanup!
Release v0.8.0
fix(client): transition from password reset confirmation to signin once reset is complete