Set source configuration to 8 per JDK-8212233

Author: Isaac Brodsky

pom.xml

@@ -282,6 +282,9 @@
                         </goals>
                     </execution>
                 </executions>
+                <configuration>
+                    <source>8</source>
+                </configuration>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -331,6 +334,9 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
                 <version>${maven.javadoc.plugin.version}</version>
+                <configuration>
+                    <source>8</source>
+                </configuration>
             </plugin>
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>