Playbook update (for linuxkit demo); misc fixes

[chungers]

This PR

• Adds some utilities for the playbook on linuxkit demo
• Add a new function for fetching from url without evaluating the contents as template

[codecov]

Codecov Report

Merging #532 into master will decrease coverage by 0.15%.
The diff coverage is 28.57%.

@@            Coverage Diff             @@
##           master     #532      +/-   ##
==========================================
- Coverage   56.73%   56.58%   -0.16%     
==========================================
  Files          57       57              
  Lines        3904     3925      +21     
==========================================
+ Hits         2215     2221       +6     
- Misses       1403     1418      +15     
  Partials      286      286

Impacted Files	Coverage Δ
pkg/template/funcs.go	61.31% <28.57%> (-3.1%)	⬇️

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