add Makefile to ease maintenance (#7267)

adding `Makefile` with `make format` and `make test` to make things
easier to maintain.

---------

Signed-off-by: Stas Bekman <stas@stason.org>

CONTRIBUTING.md

@@ -19,6 +19,12 @@ If a formatting test fails, it will fix the modified code in place and abort
 the `git commit`. After looking over the changes, you can `git add <modified files>`
 and then repeat the previous `git commit` command.
 
+You can also run:
+```
+make format
+```
+which will do the same as above, and it'll also automatically build a `venv` python environment if you
+don't already have one, which will isolate the requirements of this project from requirements of other projects.
 
 ## Testing
 DeepSpeed tracks two types of tests: unit tests and more costly model convergence tests.
@@ -38,6 +44,11 @@ You can also provide the `-v` flag to `pytest` to see additional information abo
 tests. Note that [pytest-forked](https://github.com/pytest-dev/pytest-forked) and the
 `--forked` flag are required to test CUDA functionality in distributed tests.
 
+You can also run:
+```
+make test
+```
+
 ### Model Tests
 To execute model tests, first [install DeepSpeed](#installation). The
 [DeepSpeedExamples](https://github.com/deepspeedai/DeepSpeedExamples/) repository is cloned

Makefile

@@ -0,0 +1,23 @@
+# usage: make help
+
+.PHONY: help test format
+.DEFAULT_GOAL := help
+
+help: ## this help
+	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n"} /^[0-9a-zA-Z_-]+:.*?##/ { printf "  \033[36m%-22s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)
+	echo $(MAKEFILE_LIST)
+
+test: ## run tests
+	pytest --forked tests/unit/
+
+format: ## fix formatting
+	@if [ ! -d "venv" ]; then \
+		python -m venv venv; \
+		. venv/bin/activate; \
+		pip install pre-commit -U; \
+		pre-commit clean; \
+		pre-commit uninstall; \
+		pre-commit install; \
+		deactivate; \
+	fi
+	. venv/bin/activate && pre-commit run --files $$(git diff --name-only master) && deactivate