Added Travis CI configuration file.
Tests support only Python 2.7.
Merge branch 'master' of https://github.com/mstajdohar/datastream
Code cleanup.
Minimized granularity keys. Keys are stored in every datapoint and we do not want unnecessary space consumption.
One assertion more.
API change.
Use timezone aware datetime objects.
Merge branch 'tests' of https://github.com/mstajdohar/datastream

Conflicts:
	datastream/api.py
	datastream/backends/mongodb.py
Allow disabling timestamp check in append.
Append should also check if datapoint timestamp is not in the already downsampled range.
Bugfix.
Fixed tests.
More tests and fixes.
Added comment/TODO.
Renamed "metric" into "stream".
`get_data` should return iterator and not list.
Return datapoints from newest to oldest.
Added custom class for datapoints iterator.
Version bump.