Use Moose for database handle classes

Use Test::Class for database handle tests
Bugfixes for QC when no samples fail thresholds
Merge pull request #196 from iainrb/devel

Bugfixes for QC when no samples fail thresholds
Merge pull request #190 from keithj/moose_db_handles

Use Moose for database handle classes
Incremented version number
Merge pull request #197 from iainrb/devel

Incremented version number
Merge pull request #198 from wtsi-npg/devel

Increment version number
Merge pull request #199 from wtsi-npg/release-1.2.1

Release 1.2.1