General improvements, and security fixes

[danielhaim1]

Fixed security issues and updated npm packages

1. Updated the following packages:

   • chai from v3.2.0 to v4.2.0
   • cheerio from v0.19.0 to v0.22.0
   • commander from 2.8.1 to v3.0.2
   • mocha from v2.2.5 to v6.2.0
   • webpack from v1.11.10 to v4.41.0

2. Added new packages:

   • webpack-cli v3.3.9
   • terser-webpack-plugin

3. Moved packages from "dependencies" to "devDependencies"

4. Updates to Webpack

   • Upgraded version, and improved webpack.config.js
   • Removed UglifyJS and replaced with Terser (support for ES6)

5. Fixed test/* files, w/ cheerio v0.22.0

   • Fixed a few missing semicolons
   • Replaced var with const, and added => functions
   • Test is now working with cheerio v0.22.0

6. General improvements to /src/

   • Replaced var with const when necessary
   • Replaced functions with => when possible
   • Linted files in ./src/ folder

7a. Update README.md

• Added css
• Fixed broken links

7b. Update .gitignore

• Added more files, folders

Tested functions: (no errors)

• npm run watch
• npm run test
• npm run build
• npm run build-dev
• npm run build-prod

[davidmerfield]

Nice work Daniel! Much appreciated