Enforce striter CI checks for docs and fix some doc issues that would now fail the build.

docs/Makefile

@@ -50,7 +50,7 @@ clean:
 	rm -rf $(BUILDDIR)/*
 
 html:
-	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+	$(SPHINXBUILD) -W -T -E -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
 

docs/conf.py

@@ -89,6 +89,7 @@
     'web3.providers.rst',
     'web3.providers.eth_tester.rst',
     'web3.testing.rst',
+    'web3.tools.*',
 ]
 
 # The reST default role (used for this markup: `text`) to use for all

docs/ethpm.rst

@@ -488,7 +488,7 @@ Sample standard-json-input.json
         "language": "Solidity",
         "sources": {
             "Contract.sol": {
-                "urls": [<path-to-contract>]
+                "urls": ["<path-to-contract>"]
             }
         },
         "settings": {

newsfragments/1437.doc.rst

@@ -0,0 +1,5 @@
+Enforce stricter doc checking, turning warnings into errors to fail CI builds
+to catch issues quickly.
+
+Add missing ``web3.tools.rst`` to the table of contents and fix incorrectly formatted
+JSON example.