Port `hub push` tests to cukes

features/push.feature

+Feature: hub push
+  Background:
+    Given I am in "git://github.com/mislav/coral.git" git repo
+
+  Scenario: Normal push
+    When I successfully run `hub push`
+    Then the git command should be unchanged
+
+  Scenario: Push current branch to multiple remotes
+    Given I am on the "cool-feature" branch
+    When I successfully run `hub push origin,staging`
+    Then "git push origin cool-feature" should be run
+    Then "git push staging cool-feature" should be run
+
+  Scenario: Push explicit branch to multiple remotes
+    When I successfully run `hub push origin,staging,qa cool-feature`
+    Then "git push origin cool-feature" should be run
+    Then "git push staging cool-feature" should be run
+    Then "git push qa cool-feature" should be run
+
+  Scenario: Push multiple refs to multiple remotes
+    When I successfully run `hub push origin,staging master new-feature`
+    Then "git push origin master new-feature" should be run
+    Then "git push staging master new-feature" should be run

test/hub_test.rb

@@ -161,34 +161,6 @@ class HubTest < Minitest::Test
                     "cherry-pick xoebus@a319d88"
   end
 
-  def test_push_untouched
-    assert_forwarded "push"
-  end
-
-  def test_push_two
-    assert_commands "git push origin cool-feature", "git push staging cool-feature",
-                    "push origin,staging cool-feature"
-  end
-
-  def test_push_current_branch
-    stub_branch('refs/heads/cool-feature')
-    assert_commands "git push origin cool-feature", "git push staging cool-feature",
-                    "push origin,staging"
-  end
-
-  def test_push_more
-    assert_commands "git push origin cool-feature",
-                    "git push staging cool-feature",
-                    "git push qa cool-feature",
-                    "push origin,staging,qa cool-feature"
-  end
-
-  def test_push_multiple_refs
-    assert_commands "git push origin master new-feature",
-                    "git push staging master new-feature",
-                    "push origin,staging master new-feature"
-  end
-
   def test_pullrequest_from_branch_tracking_local
     stub_config_value 'push.default', 'upstream'
     stub_branch('refs/heads/feature')