Merge branch 'master' of https://github.com/CenterForOpenScience/modular-odm into develop
Merge branch 'develop' of https://github.com/CenterForOpenScience/modular-odm into develop
More specific exceptions in DateTimeField

And add some tests
Remove some usage of raise Exception

Also,
Renames test_basic.py -> test_storedobject.py
Adds ImproperConfigurationError
Adds DatabaseError
Allow PickleStorage prefix to be None
Raise DatabaseError if assigning unsaved foreign object
Move test_exceptions.py tests -> test_storedobject.py
Saving detached object raises DatabaseError
Merge branch 'develop' of https://github.com/CenterForOpenScience/modular-odm into exceptions
Invalid validator raises TypeError
ValidationError if required field is not set
Fix bug in validating ListField default

Default cannot be a dict
Raise TypeError if default value is not a list
More specific errors in query.py
Don't publish tests package to the PyPI
Fix raising ModularOdmException in storedobject.py
Add invoke support
Move tests/__init__.py -> tests/base.py
Allow changing mongo test settings
Implement rich == comparison

Fixes error raised when comparing with None
Merge pull request #47 from sloria/comparison

Comparison