Pulls db access out for better testing

Adds a new DB API layer can easily be mocked out for No DB testing of
the components of Quark. Also refactors the IPAM tests to utilize the
new API.
Merge pull request #14 from Cerberus98/pull_out_merge_in

Pulls db access out for better testing
Only run cover on quark

* Output html reports to .cover-report
Merge pull request #15 from jkoelker/quark_cover

Only run cover on quark
Added HTTP exception handling for create_ip_address
Stop patching the wrong db api

Re-fixes DB transactions
Merge pull request #16 from Cerberus98/master

Re-fixes DB transactions
Network name filtering works again
Merge pull request #17 from Cerberus98/bugfix

Network name filtering works again
Merge pull request #18 from asadoughi/master

Fixed HTTP exceptions for create IP address responses
Merge branch 'master' of github.com:roaet/quark