Try skipping the push() test

Trying to bisect the cause of the consistent test failure on Windows.

src/test/java/org/jenkinsci/plugins/gitclient/PushTest.java

@@ -83,7 +83,7 @@ public PushTest(String gitImpl, String branchName, String refSpec, Class<Throwab
         this.expectedException = expectedException;
     }
 
-    @Test
+    // @Test
     public void push() throws IOException, GitException, InterruptedException {
         checkoutBranchAndCommitFile();