Travis commit : build 550

chore: increase version to v1.19.0

Resolves angular-ui#546

Travis commit : build 544

chore: increase version to 0.18.0

Travis commit : build 538

chore: increase version to 0.17.2

Travis commit : build 522

Travis commit : build 521

Merge pull request angular-ui#515 from thgreasi/joujiahe-master

fix(sortable): fix incorrect helper returned from getSortingHelper()

Merge pull request angular-ui#516 from thgreasi/joujiahe-v0.14.x-stable

fix(sortable): fix incorrect helper returned from getSortingHelper()