Upgrade sbt-ci-release (#68)

Author: kevinwallimann

project/plugins.sbt

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.5.12")
+addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.9.3")
 addSbtPlugin("com.eed3si9n" % "sbt-projectmatrix" % "0.9.2")
 
 addSbtPlugin("org.jetbrains.scala" % "sbt-ide-settings" % "1.1.1")