Pass paths to secrets in commandline arguments instead of secrets

This is to make sure that we don't leak keys in the argument and hence
in logs etc.

Expose a browser facing API for creating Stripe charges

When the nixpkgs revision was bumped, the stack version in use was bumped.
The newer stack version uses a different cache layout and can't find any of
the cached artifacts in the old cache.

let more "fixed" parameters come first and then the dynamic ones so
that one can do currying with the immutable parameters applied.

Stripe developer dashboard provides a few keys and we specifically
need to use the secret key.

If for "some reason" Stripe servers returned a mismatched voucher
code, return http 500 status.

Mark the voucher as paid if the stripe charge API returns a Charge
object.

The skeleton is in place, a lot of actual work still needs to be done.

Fix the direct Nix build.

Supply the warp-tls dependency and add CircleCI coverage for direct Nix builds.

Support serving either HTTP or HTTPS

Get stack to compute the doc path correctly

Pass the same flags so the snapshot is computed the same so the paths match.

???

Okay what is it