Remove mysqltuner, fetch with staging instead

mysqltuner is licensed under GPL so we don't want to package it with the
module.
Merge pull request #624 from mhaskel/FM-2112

Remove mysqltuner, fetch with staging instead
Clean up lint warnings
Merge pull request #625 from mhaskel/lint_cleanup

Clean up lint warnings
3.1.0 prep
Merge pull request #626 from mhaskel/3.1.0-prep

3.1.0 prep
Forgot to add SLES12 to metadata. yay.
Merge pull request #627 from mhaskel/metadata_fix

Forgot to add SLES12 to metadata. yay.
Merge pull request #628 from mhaskel/merge_3.1.x_into_master

Merge 3.1.x into master