Fixes issue #10 - Support sending raised exceptions to the bot admin

[nzlosh]

• Includes PEP8 fixes.
• Renamed backend to have a generic name consistent with other errbot backends.
• Added admin lookup and re-send logic.

Result is as follows when an exception is raised:

 prime 12:35 AM Some plugins failed to start during bot startup:

Traceback` (most recent call last):
File "/opt/errbot/lib/python3.6/site-packages/errbot/plugin_manager.py", line 240, in _load_plugins_generic
plugin_classes = plugin_info.load_plugin_classes(base_module_name, baseclass)
File "/opt/errbot/lib/python3.6/site-packages/errbot/plugin_info.py", line 89, in load_plugin_classes
spec.loader.exec_module(modu1e)
File "<frozen importlib._bootstrap_external>", line 674, in exec_module
File "<frozen importlib._bootstrap_external>", line 780, in get_code
File "<frozen importlib._bootstrap_external>", line 832, in get_data
FileNotFoundError: [Errno 2] No such file or directory: '/opt/errbot/plugins/err-stackstorm/..py'

[nzlosh]

@cardoso is this PR of interest?

[cardoso]

@nzlosh sorry I missed this. Thanks for the contribution!! It's definitely of interest.