Re-add Apache PATCH request (googleapis#547)

* Revert "Revert "add patch to google http client (googleapis#486)" (googleapis#493)"

This reverts commit 9de9cbb.

* Move the new handlers to the apache-transport from the legacy apache-transport

Author: chingor13

google-http-client-apache/src/main/java/com/google/api/client/http/apache/ApacheHttpTransport.java

@@ -35,6 +35,7 @@
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpHead;
 import org.apache.http.client.methods.HttpOptions;
+import org.apache.http.client.methods.HttpPatch;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.client.methods.HttpPut;
 import org.apache.http.client.methods.HttpRequestBase;
@@ -209,6 +210,8 @@ protected ApacheHttpRequest buildRequest(String method, String url) {
       requestBase = new HttpGet(url);
     } else if (method.equals(HttpMethods.HEAD)) {
       requestBase = new HttpHead(url);
+    } else if (method.equals(HttpMethods.PATCH)) {
+      requestBase = new HttpPatch(url);
     } else if (method.equals(HttpMethods.POST)) {
       requestBase = new HttpPost(url);
     } else if (method.equals(HttpMethods.PUT)) {

google-http-client-apache/src/test/java/com/google/api/client/http/apache/ApacheHttpTransportTest.java

@@ -73,6 +73,8 @@ public void testRequestsWithContent() throws Exception {
     subtestUnsupportedRequestsWithContent(
         transport.buildRequest("HEAD", "http://www.test.url"), "HEAD");
 
+    // Test PATCH.
+    execute(transport.buildRequest("PATCH", "http://www.test.url"));
     // Test PUT.
     execute(transport.buildRequest("PUT", "http://www.test.url"));
     // Test POST.