Add loading attribute for img and iframe

[pete-murphy]

Fixes #25

[pete-murphy]

😞 Build is failing here and for #27 because of an unnamed Eq instance in the bower_components

Error found:

at bower_components/purescript-web-html/src/Web/HTML/Event/DataTransfer/DataTransferItem.purs:21:17 - 21:19 (line 21, column 17 - line 21, column 19)

  Unable to parse module:

  Unexpected token 'Eq'

This seems to be because the project specifies 0.14.0 as the PureScript version (https://github.com/lumihq/purescript-react-basic-dom/blob/a1d9325a6a76c95f76444ad560ea382545bfe97d/package.json#L24), but 0.14.2 is the earliest version with optional type class instance names (https://github.com/purescript/purescript/releases/tag/v0.14.2).

I was able to bump to 0.14.5 (most recent release at time of writing) and run npm run build:pulp on this branch without issue, I'll open a separate PR to bump PureScript version.

[pete-murphy]

🎉 Build is passing now

[tippenein]

Ah, thanks for doing the lookup of the Eq issue as well! Thanks