tests for local.NewBuilder

[balopat]

Also improved a little bit the Override function to help when there is a mistake while using it in tests - originally it just threw a cryptic panic during teardown.

[codecov-io]

Codecov Report

Merging #2240 into master will increase coverage by 0.58%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #2240      +/-   ##
==========================================
+ Coverage   60.03%   60.61%   +0.58%     
==========================================
  Files         185      185              
  Lines        7794     7798       +4     
==========================================
+ Hits         4679     4727      +48     
+ Misses       2728     2683      -45     
- Partials      387      388       +1

Impacted Files	Coverage Δ
pkg/skaffold/build/local/types.go	61.76% <100%> (+8.63%)	⬆️
pkg/skaffold/runner/diagnose.go	13.04% <0%> (+13.04%)	⬆️
pkg/skaffold/kubernetes/wait.go	46.05% <0%> (+46.05%)	⬆️

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