test of Dynamic.get_dates deleted. Because get_dates_neverused
start testing resources.

tested classes:
	Resource
	TraversingMixin
tests refactored; tests.utils added;
resourses.Graph tests added.
added resources.Graphs tests.
Merge branch 'master' of https://github.com/thumbtack-technology/training-2013-correlator

Conflicts:
	correlator/resources.py
	correlator/views.py