Replace `travis` CLI addon invocation with stand-alone script

[BanzaiMan]

This replaces the ill-maintained CLI addon invocation, and provides a flexible way to test the app locally more reliably.

After this PR, we will replace script/compile with this compile.

[BanzaiMan]

@meatballhat My intention is to replace script/compile entirely. I didn't do it with this PR, because I thought that the diff would be too large to properly comprehend.

[meatballhat]

@BanzaiMan Replacing ./script/compile makes sense to me, but I don't agree with removing the ability to use the script to test local changes. I would prefer to see this replacement happen within the same PR and I promise I won't complain about the diff size :heart: I would also like the script location to be ./script/compile, or even better imho would be ./bin/travis-build-compile.

[BanzaiMan]

@meatballhat Good points. I'll make some changes.