[BUG] can't include tsconfig's paths in final build file

[ronnetzer]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[x] Bug report  
[ ] Performance issue
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request
[ ] Other... Please describe:

Current behavior

When importing a library using the tsconfig's path imports, ncc will consider it as external module and wont include it in the final build file

Expected behavior

The builder should include all used libs in the final build, it should be tree-shaken as well