feat: offline support, generator from repo, bestofui5 test

[petermuessig]

• adds offline support for Easy UI5 to use with --offline flag
• allow forceUpdate for generators via --forceUpdate flag
• allow to specify generator from conrete repository: yo easy-ui5 SAP-samples/ui5-typescript-tutorial
• bestofui5 test integration via --next flag

[petermuessig]

The most interesting file is this one: https://github.com/SAP/generator-easy-ui5/blob/be87f4e201dca032fe53ce353896e79e6d2249b3/generators/app/index.js

😉

[marianfoo]

Like the integration with BestOfUI5! Don't hit the GitHub Rate Limit anymore.

[petermuessig]

Great, thx - I'll go ahead and release a new minor version