fix(mongodb): Limit kwarg must be an int

It turns out that the limit kwarg in pymongo's find method doesn't revert to
a sensible default when "None" is passed.

Change-Id: I9070959cbcc003da49cccce33b28cc3100311f5c
Fix assertion for Testutils to check on sqlite://:memory:

The current uses sqlite://memory to test a connection. This is a faulty path to
memory. Corrent path is sqlite://:memory:

Change-Id: I950521f9b9c6aa8ae73be24121a836e84e409ca2
Merge "fix(mongodb): Limit kwarg must be an int"
Merge "Fix assertion for Testutils to check on sqlite://:memory:"