update README, simplify.
update, allow passing through key/id to helper fn
update notifier
change **airbrake to **kwargs
add airbrake_error_from_logrecord

includes style/docstring updates
change name to _notifier
util fn for checking a sys.exc_info() tuple
raise Exception if missing api_key or project_id
always use_ssl and auto_notify, remove the kwargs

removes the use_ssl and auto_nofity attributes/options

The airbrake endpoint will now always use the ssl scheme with https,
and the log() method will always call notify() when it has finished
building the error payload to post
use _context instead of _env_context
updates logic in Airbrake.log() and notifier.Error

addresses remaining comments from PR#8
add mock to test requirements
fix tests
clear exception context when finished reporting

otherwise, the context could be re-read, causing
unwanted overwrites and errors being reported more
than once, when they only occured once.
add a real test

note: if airbrake environment variables are
configured, this module will actually
ship errors to airbrake.io

The future goal for this module will be to send
subsequent queries which use the airbrake data API
to ensure that the errors were reported precisely
as expected, and then deleting those test records
remove _reset() and unneeded instance attributes

Now that the API is well understood in the module,
there is no benefit to aggregating errors in an
instance attribute list (was self.errors).

The payload is now built and shipped on each use of log()
style
fix tests
e.g. adding the AirbrakeHandler to existing logger
Update README.md