Shouldn't use logging.exception()

[hyperknot]

In the parser.py file, there is a debug log and directly after, there is a .exception log:

https://github.com/tkrajina/gpxpy/blob/master/gpxpy/parser.py#L144-L145

This is actually raising an ERROR level log, triggering all kind exception watchers like Sentry, as well as polluting the logs for benign things. The first line is a .debug() line for a reason, I believe.

This is not how exceptions should be logged in Python. You can add them to the debug line, as listed here:
https://docs.python.org/2/library/logging.html#logging.Logger.debug

[hyperknot]

PR submitted: #112

[tkrajina]

Merged, thanks.