chore: source 1.8

Author: jeremylong

pom.xml

@@ -387,7 +387,7 @@
                             <goal>jar</goal>
                         </goals>
                         <configuration>
-                            <source>1.6</source>
+                            <source>1.8</source>
                             <failOnError>false</failOnError>
                         </configuration>
                     </execution>
@@ -464,7 +464,7 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-pmd-plugin</artifactId>
                 <configuration>
-                    <targetJdk>1.5</targetJdk>
+                    <targetJdk>1.8</targetJdk>
                     <linkXref>true</linkXref>
                     <sourceEncoding>utf-8</sourceEncoding>
                 </configuration>