chore(deps): update dependency org.apache.maven.plugins:maven-compiler-plugin to v3 (#937)

Author: renovate-bot

google-http-client-findbugs/google-http-client-findbugs-test/pom.xml

@@ -11,7 +11,7 @@
     <plugins>
       <plugin>
         <artifactId>maven-compiler-plugin</artifactId>
-        <version>2.3.2</version>
+        <version>3.8.1</version>
         <configuration>
           <source>1.7</source>
           <target>1.7</target>

pom.xml

@@ -285,7 +285,7 @@
         </plugin>
         <plugin>
           <artifactId>maven-compiler-plugin</artifactId>
-          <version>2.3.2</version>
+          <version>3.8.1</version>
           <configuration>
             <source>1.7</source>
             <target>1.7</target>