Suppress error messages in unit tests

These messages are expected and only add noise to the command-line
output when the unit tests run.
Merge pull request #18 from jugglinmike/suppress-error-msgs

Suppress error messages in unit tests
Include architecture diagram in README
Merge pull request #19 from gaye/include-diagram

Include architecture diagram in README
Bug 900270 - Add support for marionette-mocha.opts r=jugglinmike
marionette-mocha.opts vbump
v0.2