Remove unneeded contrib.appengine exceptions

[pferate]

Resolving issue #465.

Possible breaking change, so probably wait to add in next major release.

[theacodes]

@nathanielmanistaatgoogle interested to see your thoughts on this breaking change.

[nathanielmanistaatgoogle]

I like the change, mostly. What valid use cases would we be breaking if we were to just incorporate this now? Do we think that developers have written code that catches appengine.InvalidClientSecretsError and does something else in response? Note that without "Raises:" in the constructor's doc string, I'm hesitant to call the raising of the exception part of the API in the first place.

[theacodes]

Do we think that developers have written code that catches appengine.InvalidClientSecretsError and does something else in response?

Probably not, this is likely something experienced when first developing and is uncaught and just manually addressed, if I had to guess. It's not exactly a "recoverable" exception.

I'm hesitant to call the raising of the exception part of the API in the first place.

Same, but even still we'll probably make the next release 3.0.0.

[pferate]

After doing some testing, this may not be considered a breaking change after all.

Since we are importing InvalidClientSecretsError in the appengine module it can still be caught as appengine.InvalidClientSecretsError, even though it is really clientsecrets.InvalidClientSecretsError. Unless users are specifically treating them differently (which isn't likely), the change should be fairly transparent.

[theacodes]

Cool. I'll likely make the next release 3.0.0 anyways because of the other changes.

[pferate]

clientsecrets.py

class InvalidClientSecretsError(Exception):
    """Main error"""

appengine.py

class InvalidClientSecretsError(Exception):
    """Duplicated error"""

appengine2.py

from clientsecrets import InvalidClientSecretsError

>>> import appengine
>>> appengine.InvalidClientSecretsError
<class 'appengine.InvalidClientSecretsError'>
>>> import appengine2 as appengine
>>> appengine.InvalidClientSecretsError
<class 'clientsecrets.InvalidClientSecretsError'>

[pferate]

Updated _parse_state_value() to return None for invalid tokens and the uri otherwise

[theacodes]

@nathanielmanistaatgoogle does this look good to merge?

[pferate]

Hold on @jonparrott , I need to add in @nathanielmanistaatgoogle's last suggestions. I've been working on moving this to py.test today (you mentioned that at the meetup last month)

[pferate]

Ok. I amended the commit to include explicitly returning None.

[nathanielmanistaatgoogle]

@jonparrott: to me this now looks ready to merge.

[theacodes]

Woot. Waiting on GodotTravis.

[theacodes]

Thanks, @pferate this is a great change. :D