Replace logrus by uber-go/zap

[gandarez]

This PR replaces the logrus logger by uber-go/zap. According to the benchmarks zap is 1677% faster than logrus.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 60.18519% with 43 lines in your changes missing coverage. Please review.

Project coverage is 63.14%. Comparing base (b60c4da) to head (490ad2c). Report is 2 commits behind head on develop.

Files with missing lines	Patch %	Lines
pkg/log/log.go	56.66%	26 Missing :warning:
pkg/log/writer.go	12.50%	14 Missing :warning:
pkg/log/context.go	0.00%	3 Missing :warning:

@@             Coverage Diff             @@
##           develop    #1119      +/-   ##
===========================================
+ Coverage    63.10%   63.14%   +0.04%     
===========================================
  Files          384      386       +2     
  Lines        16851    16881      +30     
===========================================
+ Hits         10633    10660      +27     
- Misses        5647     5650       +3     
  Partials       571      571              

Flag	Coverage Δ
unittests	63.14% <60.18%> (+0.04%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
cmd/run.go	44.32% <100.00%> (+0.57%)	:arrow_up:
pkg/log/option.go	100.00% <100.00%> (ø)
pkg/offline/offline.go	57.29% <100.00%> (ø)
pkg/project/project.go	93.25% <100.00%> (ø)
pkg/remote/remote.go	65.88% <100.00%> (ø)
pkg/log/context.go	0.00% <0.00%> (ø)
pkg/log/writer.go	12.50% <12.50%> (ø)
pkg/log/log.go	50.53% <56.66%> (+11.99%)	:arrow_up: