[yang] ensure that nif was loaded

Summary: ensure that nif was loaded

Test Plan: read change

Reviewers: aschultz, druss, hsychla

Reviewed By: druss

CC: mkraemer, druss, aschultz

Differential Revision: https://review.tpip.net/D1259
[yang] tetrapak configuration with build_nif task added

Summary: tetrapak configuration with build_nif task added

Test Plan: read, build and test on machine

Reviewers: druss, hsychla, aschultz

Reviewed By: druss

CC: mkraemer, druss, aschultz

Differential Revision: https://review.tpip.net/D1260
[yang] parse_transform added to deps, unused variables removed

Summary: parse_transform added to deps

Test Plan: read, build with tetrapak_deps

Reviewers: druss

Reviewed By: druss

CC: mkraemer, druss, aschultz

Differential Revision: https://review.tpip.net/D1264

Conflicts:
	src/yang_json_validate.erl