v1.2.0

Changelog

80087c0 added release notes
8013f81 fixed jenkinsfile test stage
9fb708a added tests to makefile and Jenkinsfile
0f6695e fixed md syntax
6e6a0ba Updated Readme with compatibility table to packer versions
ab12cf0 sorted compatibility for packer 1.5.x
5c2b679 remove vendor folder using go mod updated dependency packages