Figure out blocking CSS problem so we can get the latest version on pip

[JobLeonard]

Ok, as far as I can see, there is only one blocking issue with releasing on pip right now: the weird CSS issues.

• in order to have all external components we use work properly, we should use style-loader and css-loader and import their CSS into JavaScript (ughh.. but I digress)
• this means we now need absolute paths where relative paths worked before, complicating our build process
  • local development/viewing using localhost
  • serving the viewer on a website, for easy sharing of (data in) .loom files can point to any url
• to make things even more annoying, the pip installable version has to be for either of these options

The way around this is to extract the CSS file into a separate file again with extract-text-webpack-plugin. God, why does everything in webdev be some kind of recursive complexity?

[JobLeonard]

Fixed (I think) with https://github.com/linnarsson-lab/loom-viewer/commit/9897a496b289fdd5d7a029f69235efff8c5e1dbb