Build system upgrade (#82)

* * Build system now uses Chrome Headless
* Improved karma support for development
* Tests use the sources from /src/ instead of /bin/
* Test coverage uses Istanbul for a better future development process.

Signed-off-by: Serban Ghita <serbanghita@gmail.com>

* Minor: updated license year

* Fix: Removed "uglifyjs-webpack-plugin" which was deprecated in favor of "terser-webpack-plugin" + "uglify-js" packages.

* Added both minified and "unminified" version to the /bin/ output - like before.

* Fix: previous non-minified build contained all comments.

.gitignore

@@ -3,4 +3,4 @@ node_modules/
 coverage/
 .log
 docs/
-coverage/
+/.idea

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2012-2015 Bryce Neal
+Copyright (c) 2012-2020 Bryce Neal
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal