Set 'com.google.googlejavaformat' as automatic module name (#257)

Details:
http://branchandbound.net/blog/java/2017/12/automatic-module-name/

Fixes #248

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=185913222

core/pom.xml

diff --git a/core/pom.xml b/core/pom.xml
index 25504b5..181035e 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -143,6 +143,11 @@
                 true
               </addDefaultImplementationEntries>
             </manifest>
+            <manifestEntries>
+              <Automatic-Module-Name>
+                com.google.googlejavaformat
+              </Automatic-Module-Name>
+            </manifestEntries>
           </archive>
         </configuration>
       </plugin>