Add Makefile for convenient releasing

Makefile

@@ -0,0 +1,18 @@
+all:
+	@grep -Ee '^[a-z].*:' Makefile | cut -d: -f1 | grep -vF all
+
+clean:
+	rm -rf build/ dist/
+
+release:
+	# Check if latest tag is the current head we're releasing
+	echo "Latest tag = $$(git tag | sort -nr | head -n1)"
+	echo "HEAD SHA       = $$(git sha head)"
+	echo "Latest tag SHA = $$(git tag | sort -nr | head -n1 | xargs git sha)"
+	@test "$$(git sha head)" = "$$(git tag | sort -nr | head -n1 | xargs git sha)"
+	make force_release
+
+force_release: clean
+	git push --tags
+	python setup.py sdist bdist_wheel
+	twine upload dist/*