Merge pull request #56 from euanh/patchqueue

build: Use mock by default
Fix unittests on 32 bit systems

Bit of a hack - dynamically detecting the machine, and using that for
the assertion. It will get the development carry on for now.

fixes xenserver/planex#57
Merge pull request #58 from matelakat/fix-32-bit-issue

Fix unittests on 32 bit systems