chore(release): version and changelog for 0.18.1

chore(release): version 0.18.0 changelog and version bump

chore(release): version bump and changelog for 0.17.0

docs(readme): add the travis status widget

chore(release): version and changelog update for 0.15.0

chore(release): update versions and changelog for 0.14.0

chore(release): changelog and version for 0.13.0

chore(release): changelog and version bump for 0.12.1

chore(release): changelog and version update for 0.12.0

chore(release): 0.11.0 changelog update