Add bundle analyzer and image optimizer, update prod build flags

Fixes #278 (closed)

The documentation for the project should also be updated to explain the image optimization: https://medium.com/devops-dudes/angular-bundle-size-optimization-75294e83c149

bundle analyzer:

• https://github.com/webpack-contrib/webpack-bundle-analyzer

image optimizer, requires the following local dependencies:

• https://imageoptim.com/howto.html
• https://pngmini.com/