Fix a couple typos (#4156)

Makefile

@@ -46,7 +46,7 @@ help:
 	@echo "readme               - Regenerate README.rst file."
 	@echo "contrib              - Regenerate CONTRIBUTING.rst file"
 	@echo "clean-dist --------- - Clean all distribution build artifacts."
-	@echo "  clean-git-force    - Remove all uncomitted files."
+	@echo "  clean-git-force    - Remove all uncommitted files."
 	@echo "  clean ------------ - Non-destructive clean"
 	@echo "    clean-pyc        - Remove .pyc/__pycache__ files"
 	@echo "    clean-docs       - Remove documentation build artifacts."

docs/userguide/tasks.rst

@@ -243,7 +243,7 @@ Automatic naming and relative imports
 
 .. sidebar:: Absolute Imports
 
-    The best practice for developers targetting Python 2 is to add the
+    The best practice for developers targeting Python 2 is to add the
     following to the top of **every module**:
 
     .. code-block:: python

docs/whatsnew-4.0.rst

@@ -1056,7 +1056,7 @@ Contributed by **Ionel Cristian Mărieș**.
 Handling task connection errors
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Connection related errors occuring while sending a task is now re-raised
+Connection related errors occurring while sending a task is now re-raised
 as a :exc:`kombu.exceptions.OperationalError` error:
 
 .. code-block:: pycon