Add a new rule git_rebase_no_changes.

tests/rules/test_git_rebase_no_changes.py

@@ -0,0 +1,28 @@
+import pytest
+from thefuck.rules.git_rebase_no_changes import match, get_new_command
+from tests.utils import Command
+
+
+@pytest.fixture
+def stdout():
+    return '''Applying: Test commit
+No changes - did you forget to use 'git add'?
+If there is nothing left to stage, chances are that something else
+already introduced the same changes; you might want to skip this patch.
+
+When you have resolved this problem, run "git rebase --continue".
+If you prefer to skip this patch, run "git rebase --skip" instead.
+To check out the original branch and stop rebasing, run "git rebase --abort".
+
+'''
+
+
+def test_match(stdout):
+    assert match(Command('git rebase --continue', stdout=stdout))
+    assert not match(Command('git rebase --continue'))
+    assert not match(Command('git rebase --skip'))
+
+
+def test_get_new_command(stdout):
+    assert (get_new_command(Command('git rebase --continue', stdout=stdout)) ==
+            'git rebase --skip')