Merge branch 'release/0.21.0' into develop
Change name of --ablation metavar in run_experiment
Update run_experiment documentation to mention how ablation mode works now.
added gamma to default parameter search grid for svc
Merge pull request #85 from EducationalTestingService/feature/svc_gamma_tuning

Add gamma to default parameter search grid for SVC.
Add testing for 2.6
Merge branch 'develop' of github.com:EducationalTestingService/skll into develop
Remove 2.6 from Travis, since I put it in by accident.
Switch license to BSD 3 clause.
Add support for wheel packaging.
Merge branch 'develop' of github.com:EducationalTestingService/skll into develop
Add --verbose flag to run_experiment to simplify debugging.
Merge branch 'develop' of github.com:EducationalTestingService/skll into develop
Update documentation
Fix issue where verbose flag wasn't working with run_experiment
Remove extra import from run_experiment
Fixed bug in _write_summary_file() that prevented writing of
summary files for 'ablation all' experiments.
Fixed accidental typo in experiments.py
Small tweak to logging in FilteredLeaveOneLabelOut to try to reduce number of calls to getLogger.
Merge branch 'develop' of github.com:EducationalTestingService/skll into develop