v3.1.2

Bugfixes:
* fix error on empty columns
* fix chromosome comparison check

Merge pull request #353 from bcgsc/release/v2.2.12

Release/v2.2.12

Merge pull request #349 from bcgsc/Release/v3.1.1

Release/v3.1.1

Merge pull request #339 from bcgsc/release/v3.1.0

Release/v3.1.0

Merge pull request #314 from bcgsc/release/v3.0.0

Release/v3.0.0

Merge pull request #268 from bcgsc/release/2.2.11

Release/2.2.11

Merge pull request #235 from bcgsc/release/v2.2.9

Release/v2.2.9

Merge pull request #230 from bcgsc/Release/v2.2.8

Release/v2.2.8

Merge pull request #222 from bcgsc/release/v2.2.7

Release/v2.2.7

Merge pull request #199 from bcgsc/develop

v2.2.6 scope review 2