Extract production build into own npm package

[enzy]

To speedup project builds on CI and deploy servers. Strip all development packages.

mango-cli will then include this lib as dependency.

Idea by @Mikulas

[enzy]

Extracted into https://github.com/manGoweb/mango-cli-core

But more work need to be done:

• reuse mango-cli-core as package (extend core and build on it)
• tests
• docs

[Mikulas]

🔝 💯