Update to sbt 0.13.6

Among other improvements, this also defaults to HTTPS-based fetching of
Maven Central dependencies.

Issue: SNX-4
Update release settings for Maven Central.

See also https://issues.sonatype.org/browse/OSSRH-11912

Issue: SNX-4
Update instructions for use with Maven Central.

Issue: SNX-4
Setting version to 1.0.1
Setting version to 1.1-SNAPSHOT
Merge branch 'feature/SNX-4-publish-1.0.1-to-maven-central' into release/1.0