fix(terraform.go): remove trailing newline from output value

[vdice]

• Removes the trailing newline from the output value returned from terraform output <output name> prior to bubbling up

Fixes #20

Note: Although the --json format flag on terraform output looks handy (as noted in #20 (comment)) it appears the terraform CLI appends the newline character in this case as well -- and we'd have the extra task of removing the wrapping double quotes. Hence, I went the simpler route and stuck with the default format.

[vdice]

@carolynvs I added a check to the current cli tests but have also created an issue around your suggestion to look into possibilities for unit test coverage in the future: #51

[carolynvs]

Is the extra check here necessary now that we are doing the exact equality check above? If there was a newline, wouldn't the != "bar" catch it?

[vdice]

Great question. Alas, bash's default command substitution strips trailing newline characters. I've been looking into ways to work around this (https://stackoverflow.com/questions/15184358/how-to-avoid-bash-command-substitution-to-remove-the-newline-character has been particularly helpful), but they seem to quickly grow ungainly. I also see that I should create a function to validate a given output, as we do so after install as well; so I'll at least update to DRY that up...

[carolynvs]

LGTM, thanks!