Add a nomulus renew_domain command

This may come in handy when dealing with URS requests.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=199332085

javatests/google/registry/tools/server/testdata/domain_renew.xml

@@ -0,0 +1,13 @@
+<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
+  <command>
+    <renew>
+      <domain:renew
+       xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
+        <domain:name>%DOMAIN%</domain:name>
+        <domain:curExpDate>%EXPDATE%</domain:curExpDate>
+        <domain:period unit="y">%YEARS%</domain:period>
+      </domain:renew>
+    </renew>
+    <clTRID>RegistryTool</clTRID>
+  </command>
+</epp>