Unify docs, test dev env

Makefile

@@ -54,10 +54,10 @@ dev/%: PORT?=8888
 dev/%: ## run a foreground container for a stack
 	docker run -it --rm -p $(PORT):8888 $(DARGS) $(OWNER)/$(notdir $@) $(ARGS)
 
-test-reqs: # install libraries required to run the integration tests
-	pip install -r requirements-test.txt
+dev-env: # install libraries required to build docs and run tests
+	conda env create -f environment.yml
 
-test/%:
+test/%: ## run tests against a stack
 	@TEST_IMAGE="$(OWNER)/$(notdir $@)" pytest test
 
 test/base-notebook: ## test supported options in the base notebook

environment.yml

+name: docker-stacks
+channels:
+  - conda-forge
+dependencies:
+- python=3.6
+- pytest
+- requests
+- sphinx>=1.6
+- sphinx_rtd_theme
+- pip:
+  - docker
+  - jupyter_alabaster_theme
+  - recommonmark==0.4.0
\ No newline at end of file

readthedocs.yml

+conda:
+    file: environment.yml
+python:
+    version: 3
\ No newline at end of file

requirements-test.txt

-docker
-pytest
-requests
\ No newline at end of file