Remove all Scala/Akka dependencies

Remove all Scala/Akka dependencies

Akka has a next major release train, 2.6.x, which simply does not
work with OSGi unless we repackage it. Upstream is not interested
in fixing this problem and in fact is geared towards completely
removing OSGi support.

Completely remove any mention of Akka/Scala in odlparent, so that
controller and other downstreams can do their thing to use Akka
whichever way they see fit.

JIRA: ODLPARENT-243
Change-Id: Iab6fcd59d04cdd1abdefaa9f24d5582f28169fd4
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>