Get charm to build

This is still missing the charm.openstack module dependency

Makefile

@@ -1,7 +1,8 @@
 #!/usr/bin/make
+LAYER_PATH := layers
 
 clean:
-	rm -Rf build
+	rm -Rf build .tox
 
 generate: clean
-	tox -e generate
+	LAYER_PATH=$(LAYER_PATH) tox -e generate

requirements.txt

@@ -1 +1,2 @@
 charm-tools
+simplejson

tox.ini

@@ -18,7 +18,7 @@ deps =
 [testenv:generate]
 basepython = python2.7
 commands =
-    charm build --log-level DEBUG -o {toxinidir}/build barbican
+    charm build --log-level DEBUG -o {toxinidir}/build charm
 
 [testenv:venv]
 commands = {posargs}