Remove makefile and use tox.ini from basic layer to pin it

cluster/juju/layers/kubernetes-master/Makefile

@@ -1,25 +0,0 @@
-#!/usr/bin/make
-
-all: lint unit_test
-
-
-.PHONY: clean
-clean:
-	@rm -rf .tox
-
-.PHONY: apt_prereqs
-apt_prereqs:
-	@# Need tox, but don't install the apt version unless we have to (don't want to conflict with pip)
-	@which tox >/dev/null || (sudo pip install tox)
-	@sudo apt-get install -y python-pip python-flake8 python3-flake8 flake8
-
-.PHONY: lint
-lint: apt_prereqs
-	@tox --notest
-	@flake8 $(wildcard hooks reactive lib unit_tests tests)
-	@charm proof
-
-.PHONY: unit_test
-unit_test: apt_prereqs
-	@echo Starting tests...
-	tox

cluster/juju/layers/kubernetes-master/tox.ini

@@ -0,0 +1,12 @@
+[tox]
+skipsdist=True
+envlist = py34, py35
+skip_missing_interpreters = True
+
+[testenv]
+commands = py.test -v
+deps =
+    -r{toxinidir}/requirements.txt
+
+[flake8]
+exclude=docs