adding "htmlproof" npm script command.

README.md

@@ -5,7 +5,7 @@ We are using Jekyll to generate the static html files.
 https://jekyllrb.com
 
 ### Requirements (mac)
-* Ruby: `brew install ruby`
+* Ruby: `brew install ruby` (v2.3.3 works, v2.4.0 *does not*)
 * Ruby Gems: https://rubygems.org/pages/download
 * NodeJS: https://nodejs.org/en/ (Ideally >=4.5.0)
 * Python: `brew install python`
@@ -40,6 +40,8 @@ Production builds should be handled by CI.
 
 `npm run build` will build a fully minified, mangled, and compressed build to the _site directory.
 
+ `npm run htmlproof` will run ImageCheck, ScriptCheck, and LinkCheck on the built "_site" folder "*.html" files. Travis CI will not deploy unless this command finishes successfully!
+
 Mac
 xcode-select --install
 gem install nokogiri

package.json

@@ -9,6 +9,7 @@
     "uglify:dist": "mkdir -p dist/js/ && ./node_modules/uglify-js/bin/uglifyjs src/js/*.js -m -o dist/js/main.min.js",
     "uglify:dev": "mkdir -p dist/js/ && ./node_modules/uglify-js/bin/uglifyjs src/js/*.js -c -o dist/js/main.min.js",
     "uglify": "npm run uglify:dist",
+    "htmlproof": " htmlproofer ./_site --disable-external --allow-hash-href --assume-extension --alt-ignore '/.*/' --file-ignore /assets/,/dist/,/style-guide/,/blog/",
     "test": "echo \"No Tests.\" && exit 0",
     "clean:dist": "rm -rf dist && rm -rf _site",
     "clean": "npm run clean:dist",