Run SSH e2e test only if SSH keys are present

Not all CI systems support ssh keys to be present on the node. This
supports the case where "local" provider is being used when running
e2e test, but the environment does not have a SSH key.

test/e2e/ssh.go

@@ -34,6 +34,10 @@ var _ = framework.KubeDescribe("SSH", func() {
 	BeforeEach(func() {
 		// When adding more providers here, also implement their functionality in util.go's framework.GetSigner(...).
 		framework.SkipUnlessProviderIs(framework.ProvidersWithSSH...)
+
+		// This test SSH's into the node for which it needs the $HOME/.ssh/id_rsa key to be present. So
+		// we should skip if the environment does not have the key (not all CI systems support this use case)
+		framework.SkipUnlessSSHKeyPresent()
 	})
 
 	It("should SSH to all nodes and run commands", func() {