Use a package manager for client side libraries

[psiinon]

This is to allow us to be warned when client side libraries become out of date or have vulnerabilities reported against them.
This is part of the security checklist #31 so see that for more details of the recommended approaches.

[psiinon]

Any progress on this?
FYI I've enabled the github 'Data services' in case it picks up any vulnerabilities for existing dependencies. Unfortunately I dont think this will detect any in the client libraries until a package manager is used.

[lancecummings]

Hi @psiinon. Sorry for not getting on this sooner. I've implemented the Yarn package manager in a new Branch waiting for merge into Master: #37

[psiinon]

Nice :)