bump to jdk 1.8
diff --git a/pom.xml b/pom.xml
index 65c00a9..539520d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -59,8 +59,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>1.6</source>
-                    <target>1.6</target>
+                    <source>1.8</source>
+                    <target>1.8</target>
                 </configuration>
             </plugin>
             <plugin>