Revert "Make sbt-scoverage depend on scala version."

This reverts commit f8ab1ed1844c280934c659509f714cb60e2eca7c.
Revert "Add missing coveralls settings in build definition."

This reverts commit 3bbc028c2dc9d5b9350c959ff19a08047b3bea68.
Revert "Update sbt-coveralls to 0.99.0"

This reverts commit d790c1dd0fb638fa20c2a11db645af68e7084f19.