Bump org.scala-lang:scala-compiler from 2.11.8 to 2.11.12 in /scala

Bumps [org.scala-lang:scala-compiler](https://github.com/scala/scala) from 2.11.8 to 2.11.12.
- [Release notes](https://github.com/scala/scala/releases)
- [Commits](https://github.com/scala/scala/compare/v2.11.8...v2.11.12)

---
updated-dependencies:
- dependency-name: org.scala-lang:scala-compiler
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

scala/pom.xml

@@ -34,7 +34,7 @@
     <maven.compiler.source>1.5</maven.compiler.source>
     <maven.compiler.target>1.5</maven.compiler.target>
     <encoding>UTF-8</encoding>
-    <scala.version>2.11.8</scala.version>
+    <scala.version>2.11.12</scala.version>
     <spark.version>2.0.2</spark.version>
     <scala.binary.version>2.11</scala.binary.version>
   </properties>