I just cloned Packer from the master branch, and via a (very) crude mechanism looked at the number of lines of code in `_test.go` files vs the number of lines o

I just cloned Packer from the master branch, and via a (very) crude mechanism looked at the number of lines of code in `_test.go` files vs the number of lines of code in `.go` files which do not have the `test` build tag, excluding vendored libraries. There are approximately 60,000 lines of test code, vs 149000 lines of non-test code. Other HashiCorp products have a much higher test to production code ratio, but it is by no means uniformly 10:1.