Add pre-publish build step to fix installing insect from npm

[n4bb12]

Fixes #224

I renamed the postinstall script to setup to avoid it being run when used as a CLI tool or dependency.

The setup and build script are run in the prepack phase of the publish command, so you don't need to do anything. Just run npm publish as per usual.

For convenience the setup script is also run on npm start. It's fast, so it's ok to do that and it's convenient to not need to think about any of this when contributing.

I listed the files required for publishing in the package.json to avoid uploading unnecessary files. From testing it seems to only need the output folder to run. If I'm mistaken, please correct me. I also added the insect.png because it is used in the README. README, LICENSE and index.js are included by default.

As a small improvement I changed the copy script to copy files in parallel.

You can try this out:

# terminal 1
npx verdaccio

# terminal 2
export npm_config_registry=http://localhost:4873
npm version patch
npm publish
npx insect@5.4.1 '1 + 1'

If you want to just see what's being published and the above does not work, you can also do

npm pack

This will give you the archive that would be published and you can just open it and have a look inside.

[sharkdp]

Thank you very much for working on this!

For some reason, the build fails: https://travis-ci.org/github/sharkdp/insect/builds/730488027

I have to admit that it currently also fails on master (it used to work, and the tests still run fine locally) .... but with a different error message: https://travis-ci.org/github/sharkdp/insect/builds/730376983

[n4bb12]

I don't know why purescript is installed manually in the travis config. I think it shouldn't be because it's already installed through npm and that would also make it different from the local setup.

I also updated the build dependencies, maybe it fixes something.

[n4bb12]

Fixed ✨

[sharkdp]

Thank you so much!