Use the default Java compiler instead of error-prone:

Error-prone does not support Java 10 yet. A setup to activate
it conditionally would be too verbose (a profile activation
in each sub-module, because it does not work for
<build><pluginManagement>...).

See google/error-prone#860

pom.xml

@@ -34,33 +34,15 @@
   <build>
      <pluginManagement>
        <plugins>
-         <!-- Use Error Prone Compiler by default -->
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.7.0</version>
            <configuration>
-             <!-- Enables Error Prone (http://errorprone.info/docs) during compilation. -->
-             <compilerId>javac-with-errorprone</compilerId>
              <showWarnings>true</showWarnings>
-             <forceJavacCompilerUse>true</forceJavacCompilerUse>
              <source>${java.compiler.source}</source>
              <target>${java.compiler.target}</target>
            </configuration>
-           <dependencies>
-             <dependency>
-               <groupId>org.codehaus.plexus</groupId>
-               <artifactId>plexus-compiler-javac-errorprone</artifactId>
-               <version>2.8.4</version>
-             </dependency>
-             <!-- override plexus-compiler-javac-errorprone's dependency on
-                  Error Prone with the latest version -->
-             <dependency>
-               <groupId>com.google.errorprone</groupId>
-               <artifactId>error_prone_core</artifactId>
-               <version>2.3.1</version>
-             </dependency>
-           </dependencies>
          </plugin>
 
          <!-- Checkstyle plugin is run during validate phase (before javac) -->