quick commit
Changed the way error handling happens to support path traceback.

Needs some message tweaking, but passes current tests.
Added tests for data and new test_annotations.py file.

Changes in graph_objs.py were made to solve bugs found in new testing.
Changed instance of PlotlyAccountError to PlotlyLocalCredentialsError.

PlotlyAccountError is reserved for server errors where an actual check
has been done.

In addition, the error message for the PlotlyLocalCredentialsError is
stored in exceptions.py for better use-ability.
Added circle.yml from master for testing before merge.
Merge branch 'exceptions'

New exception handeling for better error messages.

See exceptions.py and graph_objs.py (most effected)
version bump -> 1.0.15 (exception handling)