[WIP] remove release branch/long branch names

[balvig]

Testing out:

• Removing automatic release branch targeting
• Removing PR title as part of branch name

...to clean up branch names and see if we miss it.

[sogamoso]

Very glad to see master being removed from every branch name cp8_cli creates!

[balvig]

Having tested it for a while, https://github.com/cookpad/cp8_cli/pull/21 seems much more promising.