add better example for heroku deploy script

[soenkehahn]

This adds a more comprehensive example. It's currently failing on CI because heroku is not installed there. So maybe this is blocked by #114?

[matthandlersux]

👍

what do you think about moving test/examples => examples? the readme mentions the location of these, but it's nice when you can see it as a top level folder without having to look for them.

[soenkehahn]

Sounds like a good idea.

[hallettj]

Once again on my machine executables are in weird places. I have rustup and heroku installed via Nix; the $PATH variable in the heroku example protocol does not include the directory with Nix-installed executables, so the tests are failing for me. I think the ideal solution would be to prepend to $PATH instead of replacing its content, or to avoid changing $PATH at all.

Also the new tests require the heroku app to be installed. Could we make a section in the documentation to list test prerequisites and list heroku there as a dependency?

[soenkehahn]

@hallettj: I was thinking we could implement #114 before merging this. Then it would work on all machines. (It's also failing on CI right now, since heroku is not installed there.)

[data-pup]

++ to the examples/ point made by @matthandlersux above. The examples/ is also special in that it is automatically compiled when you run your tests, so that they don't go out of date.

https://doc.rust-lang.org/cargo/reference/manifest.html#examples