docs: Add a target to build docs locally for testing.

Author: feanil

Makefile

@@ -10,7 +10,7 @@ help: ## display this help message
 	@echo "Please use \`make <target>' where <target> is one of"
 	@perl -nle'print $& if m{^[\.a-zA-Z_-]+:.*?## .*$$}' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m  %-25s\033[0m %s\n", $$1, $$2}'
 
-.PHONY: requirements develop clean diff.report view.diff.report quality static
+.PHONY: requirements develop clean diff.report view.diff.report quality static docs
 
 requirements:  ## install base requirements
 	pip3 install -q -r requirements/base.txt
@@ -144,3 +144,6 @@ travis_docker_push: travis_docker_tag travis_docker_auth ## push to docker hub
 	docker push "openedx/analytics-data-api:$$TRAVIS_COMMIT"
 	docker push 'openedx/analytics-data-api:latest-newrelic'
 	docker push "openedx/analytics-data-api:$$TRAVIS_COMMIT-newrelic"
+
+docs:
+	tox -e docs

tox.ini

@@ -3,21 +3,19 @@ skipsdist = True
 envlist = py38-django{22,30,31}-{check_isort,pycodestyle,pylint,isort,tests}
 
 [testenv]
-envdir = 
-	py38: {toxworkdir}/py38
-passenv = 
+passenv =
 	ELASTICSEARCH_LEARNERS_HOST
 	COVERAGE_DIR
-setenv = 
+setenv =
 	tests: DJANGO_SETTINGS_MODULE = analyticsdataserver.settings.test
 	NODE_BIN = ./node_modules/.bin
 	PATH = $PATH:$NODE_BIN
-deps = 
+deps =
 	django22: Django>=2.2,<2.3
 	django30: Django>=3.0,<3.1
 	django31: Django>=3.1,<3.2
 	-r requirements/test.txt
-commands = 
+commands =
 	check_isort: isort --check-only --recursive --diff analytics_data_api/ analyticsdataserver/
 	isort: isort --recursive analytics_data_api/ analyticsdataserver/
 	clean: coverage erase
@@ -27,3 +25,17 @@ commands =
 	coverage: coverage html
 	coverage: coverage xml
 
+[testenv:docs]
+deps =
+    -r{toxinidir}/requirements/doc.txt
+allowlist_externals =
+    make
+    env
+setenv =
+# -W will treat warnings as errors.
+    SPHINXOPTS = -W
+commands =
+# -e allows for overriding setting from the environment.
+# -C changes the directory to `docs` before running the command.
+    make -e -C docs/api clean
+    make -e -C docs/api html