update Travis badge
a bunch of deprecations
update sbt launcher
Setting version to 7.1.0-RC1
Setting version to 7.1.0-SNAPSHOT
MaybeInstances should be abstract class
fix -doc-source-url
Use typesafe equality in an example

This prevents the sort of breakage in
c5980d619dd624288180383125a5dc09ed6b997e (which fixed a (spurious)
warning which should have been an error).