Integration tests for common runtimes

[aron]

I'm currently in the process of spending some spare time improving the structure of this repository. Ideally I want us to get to the point where we have three things:

1. a native esm friendly version of the repository (not just relying on the nodejs dual module system)

2. the index.d.ts generated automatically using tsc --emitDeclarationOnly.

3. a singleton instance of Replicate as the default export for the package so our examples can be as simple as:

   const replicate = require("replicate");
   replicate.run(...);

   I'll follow up on this one in a second PR with more details and we'll still retain the constructor as a way of customizing the library.

This commit adds some basic integration tests and a new ci workflow for our three common runtimes, nodejs with commonjs and esm as well as TypeScript. The aim here is to ensure that the interface is consistent even if we refactor/restructure the package.

The change does require a REPLICATE_API_TOKEN to be available in the CI environment which I've added.

[zeke]

singleton instance

😍

[zeke]

Love this!

I added a few suggestions for renamed test inputs, partly for fun, but also to make them more distinguishable from each other in case of possible test failures.