Inline var setting + overwriting

vars can now be set inline. Props from files will be overwritten.

env({
  file: ".env.json",
  vars: {
    mad: "props"
  }
})

Test coverage + JSON handling

JSON was actually already handled, now it's explicit and has test coverage.

module route fix

updates require to specify files ../../ above them. Feels like a hack, but couldn't find anything built-in to handle it.

First Release

Attaches env vars to process.env from a filename.

this version only handles files that export the object:

module.exports = {
  ENV_VAR: "value"
}