use default rubygems deploy steps

shipit.rubygems.yml

@@ -1,15 +1 @@
-dependencies:
-  override:
-    - bundle install --path=./data/bundler
-
-deploy:
-  override:
-    - |
-      BUILD=`bundle exec rake build`
-      if [ $? != 0 ]; then
-        echo $BUILD;
-        exit 1;
-      fi
-      PKG=`echo $BUILD | cut -d" " -f5 | sed -e s/\.$//`;
-      VERSION=`echo $BUILD | cut -d" " -f2`;
-      gem push $PKG
+# using the default shipit config