Add support for quickstart apps

[moritzraho]

and --org --project flags

[codecov]

Codecov Report

Merging #679 (91e4783) into master (8863c0c) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #679   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           56        56           
  Lines         3188      3232   +44     
  Branches       599       611   +12     
=========================================
+ Hits          3188      3232   +44     

Files	Coverage Δ
src/commands/app/init.js	100.00% <100.00%> (ø)

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[moritzraho]

lgtm, nit: we could remove the todos and commented code, up to you.

(I can't explicitly approve because I submitted the PR at first. So putting this emoji instead 🍏)