Update build steps in makefile

Makefile

@@ -1,16 +1,26 @@
 PATH := build/python/bin:$(PATH)
 VERSION = $(shell python setup.py --version)
 ALLFILES = $(shell echo bottle.py test/*.py test/views/*.tpl)
+VENV = build/venv
 
 .PHONY: release coverage install docs test test_all test_25 test_26 test_27 test_31 test_32 test_33 2to3 clean
 
-release: test_all
-	python setup.py --version | egrep -q -v '[a-zA-Z]' # Fail on dev/rc versions
-	git commit -e -m "Release of $(VERSION)"           # Fail on nothing to commit
-	git tag -a -m "Release of $(VERSION)" $(VERSION)   # Fail on existing tags
-	git push origin HEAD                               # Fail on out-of-sync upstream
-	git push origin tag $(VERSION)                     # Fail on dublicate tag
-	python setup.py sdist register upload              # Release to pypi
+release: venv
+	$(VENV)/bin/python3 setup.py --version | egrep -q -v '[a-zA-Z]' # Fail on dev/rc versions
+	git commit -e -m "Release of $(VERSION)"            # Fail on nothing to commit
+	git tag -a -m "Release of $(VERSION)" $(VERSION)    # Fail on existing tags
+	git push origin HEAD                                # Fail on out-of-sync upstream
+	git push origin tag $(VERSION)                      # Fail on dublicate tag
+	$(VENV)/bin/python3 setup.py sdist bdist_wheel      # Build project
+	$(VENV)/bin/twine upload                            # Release to pypi
+
+venv: $(VENV)/.installed
+$(VENV)/.installed: Makefile
+	python3 -mvenv $(VENV)
+	$(VENV)/bin/python3 -mensurepip
+	$(VENV)/bin/pip install -U pip
+	$(VENV)/bin/pip install -U setuptools wheel twine coverage
+	touch $(VENV)/.installed
 
 coverage:
 	-mkdir build/
@@ -63,4 +73,3 @@ clean:
 	find . -name '*~' -exec rm -f {} +
 	find . -name '._*' -exec rm -f {} +
 	find . -name '.coverage*' -exec rm -f {} +
-