Fix bare excepts

[acmiyaguchi]

PR #191 adds local flake8 testing. To get around failing flak8 tests, there are various #noqa statements around bare except statement around the code base. These should be modified for proper exception handling.

[robhudson]

I just filed this as well. Oops. https://bugzilla.mozilla.org/show_bug.cgi?id=1437634