Upgrade to maven-compiler-plugin 3.6.1

Release notes:

https://mail-archives.apache.org/mod_mbox/maven-announce/201610.mbox/%3Cop.yp5p3mm2kdkhrr%40desktop-2khsk44.dynamic.ziggo.nl%3E
https://mail-archives.apache.org/mod_mbox/maven-announce/201701.mbox/%3Cop.yt54c2k6kdkhrr%40desktop-2khsk44%3E

pom.xml

@@ -94,7 +94,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-compiler-plugin</artifactId>
-        <version>3.5.1</version>
+        <version>3.6.1</version>
         <configuration>
           <compilerId>javac-with-errorprone</compilerId>
           <forceJavacCompilerUse>true</forceJavacCompilerUse>