Remove documentation project title config option

Nothing in the Nomulus release was using it and it's of questionable utility at
best. Nomulus isn't likely to be renamed at this point anyway.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=141301871

java/google/registry/config/TestRegistryConfig.java

@@ -106,11 +106,6 @@ public class TestRegistryConfig implements RegistryConfig {
     return makeUrl("http://www.referral.example/path");
   }
 
-  @Override
-  public String getDocumentationProjectTitle() {
-    return "Nomulus";
-  }
-
   @Override
   public int getEppResourceIndexBucketCount() {
     return 2;