add_comment() silently fails if posting to an invalid/inaccessible bug

[edmorley]

eg:

import bugsy
bz = bugsy.Bugsy(username=REDACTED, api_key=REDACTED)
bug = bugsy.Bug(bugsy=bz, id=111111111111111111)
bug.add_comment("foo")
# No exception was generated

Expected:
Command doesn't silently fail. Instead some instance of BugsyException is raised.

Note that whilst this example manually generates the bug object, the same could happen if a bug was made private after the .get() but before the .add_comment(), or if say the bug comment was too long - which causes Bugzilla to return an error even though the .get() might have succeeded.

[edmorley]

There likely needs to be a raise_for_status() wrapped in a try-except converting it to a BugsyException, after the .post() here:

Bugsy/bugsy/bug.py

Lines 271 to 275 in 436ac23

	self._bugsy.session.post(
	'%s/bug/%s/comment' % (self._bugsy.bugzilla_url,
	self._bug['id']),
	data={"comment": comment}
	)

And similar for #24.