Added QPS and Burst overrides

[craig-willis]

Fixes #289

This adds the QPS and Burst configuration overrides for the kube client. I've set defaults at 50/100, which works for the CHEESEHub case.

To test:

• Deploy this apiserver
• Run the https://github.com/cheese-hub/loadtest

[bodom0015]

Test worked well, although my dev system was a bit too small for 30 users. I may need to retest against production after merging.

Minor notes/feedback:

• We may want to add a note/reminder in the docs about updating the host variable in the postman template, as I may have accidentally run some containers on cheesehub prod while trying to test against my dev instance
• "Clean up containers" instructions says 20 instead of 30
• If possible, it might be helpful to parameterize the number of instances (eventually - not required as a part of this PR)