[fixes #50784619] - pull bosh release from jenkins artifacts bucket rather than creating one from master
Decompose ci rake tasks
Extract classses to slim rake tasks
Split HM integration tests to deal with the 10min Travis timout

Travis build will be terminated if there hasn't been any log output
in 10 min. Latest tests added to HM integration spec had increased
the build time, so every build is failing due to the timeout.
[#49306843] Refactor existing RDS migration

Add new helper RdsDb class
Explicitly create only ccdb, uaadb, mysql-service-public,
mysql-service-cf-internal databases
Add new WIP migration for BOSH rds db
[#49306843] Pull RdsDb helper class into MigrationHelper
[#49306843] Refactor BOSH RDS migration to use helper class

First two examples for BOSH RDS migration passing
[#49306843] - aws migration with utf8 params
update the migrator to record migration after each migration rather than after the batch