Automate the version injecting workflow

[zmrhaljiri]

The WebpackAutoInject plugin is increasing the version property in package.json.

There are 3 available options, each increasing different number:

• Major - from 1.0.0 to 2.0.0
• Minor - from 1.0.0 to 1.1.0
• Patch - from 1.0.0 to 1.0.1

Currently, every time build is run, it increases the version by 1 (patch option).

Suggestion is to create an argument to the build script that would apply the specified option. Also with letting patch to by the default option.

Examples:
npm start build - default, for patch change
npm start build --env.minor - for minor change
npm start build --env.major - for major change