Add support of lein "is not task"

thefuck/rules/lein_not_task.py

@@ -0,0 +1,15 @@
+import re
+
+
+def match(command, settings):
+    return (command.script.startswith('lein')
+            and "is not a task. See 'lein help'" in command.stderr
+            and 'Did you mean this?' in command.stderr)
+
+
+def get_new_command(command, settings):
+    broken_cmd = re.findall(r"'([^']*)' is not a task",
+                            command.stderr)[0]
+    new_cmd = re.findall(r'Did you mean this\?\n\s*([^\n]*)',
+                         command.stderr)[0]
+    return command.script.replace(broken_cmd, new_cmd, 1)