Halyard 0.27.0

fix(ui): show changelog
fix(deploy): Multi VM ssh woes (#519)
fix(deploy): Better error for omitted sidecar (#518)
fix(deploy): Allow settings.js to be overridden (#517)
fix(aws): Configure aws provider (#515)
fix(deploy): Custom rosco profiles (#516)
feat(cli): Adds edit provider command (#514)
fix(authz): Remove --fiat feature flag in lieu of security.authz.enabled as the source of truth (#513)
feat(validation): Support AWS assumeRole and setting credentials at the command line (#508)
fix(rollback): Fail early when rollback impossible (#512)
fix(version): 'nightly' is no longer a valid alias (#511)
fix(bake): Don't install monitoring api until after bake (#510)
Add userdata flag to halyard. (#509)
docs(core): Document how to add a parameter (#500)