Adds AppEngine support to pyrollbar module (fixes #42)

[fjorgemota]

Please, check that change with the maximum attention. I feel much like the code is a bit duplicated (just some lines have been modified), but that's all for using pyrollbar with AppEngine. (checked as working in dev_appserver.py of AppEngine's SDK)

And it fixes issue #42, too. =)

Thanks. =)

[brianr]

Thanks for the PR, @fjorgemota ! We'll get this reviewed and merged shortly.

[fjorgemota]

Awesome, thanks @brianr. I'll await a review. =)

[coryvirok]

I've verified that this works in my dev environment although I had to go through some crazy hoops to get it working with App Engine, (http://stackoverflow.com/questions/16192916/importerror-no-module-named-ssl-with-dev-appserver-py-from-google-app-engine/16937668#16937668)

Thanks for the PR!

[fjorgemota]

Awesome, thanks, @coryvirok! :D

[ekampf]

@fjorgemota @coryvirok if you're on AppEngine, you probably are not using (and don't have) the 'requests' library... which means you'll fail on init.py "import requests" no?

[fjorgemota]

@ekampf Hey, i'm using this module in production at matrufsc2.appspot.com (the repository is here: http://github.com/matrufsc2/matrufsc2) and it seems to work correctly, even with that line on init.py file.

Are you suffering from a related caused by that line?

Thanks.

[ekampf]

@fjorgemota yes. my code throws on that line (and if I comment it out on it crashes on line #1177:

if isinstance(resp, requests.Response):

in _parse_response

How come your code successfully imports requests? its not part of the default app engine stack...

[fjorgemota]

@ekampf As I remember, seems like you can INSTALL requests normally (in my case, I installed it using gaenv, which allow the use of any library in Pypi easily in AppEngine), but you CANNOT use requests to make requests.

Because this my project can import requests, but uses the GAE support added in this pull request to send exception from AppEngine's Python environment to Rollbar using URLFetch. =)

[ekampf]

@fjorgemota got it!
Still would be nice if you wouldn't have to install requests at all (as its not being used)