Rails stack

[spk]

Allow a rails new project to run directly on upsun, ref #205

• make it work on platformsh too

[akalipetis]

We should handle the following cases as well to be able to move this forward:

1. Install Bundler (if Gemfile.lock exists)
2. Install dependencies
3. Use the proposed Rails and Bundler environment variables

A great deal of work has been done in our Rails template, we should follow the same logic here: https://github.com/platformsh-templates/rails/blob/master/.platform.app.yaml

We might not need to do all the cache directory optimizations, but most of the work in there is valid.

/cc @chadwcarlson @gilzow for confirmation and maybe selection of the MVP for this.

[spk]

Yes I know those options I documented them from Ori work, the goal is to have a simple working bootstrap with Rails not a perfect one

[spk]

Can we give it a go and improve things later?

[akalipetis]

LGTM

@spk feel free to check the proposed changes and merge (or let me know to merge myself)

[spk]

LGTM thanks @akalipetis