add canary

[GwonsooLee]

Fixes: #113 Related: Relevant tracking issues, for context Merge before/after: Dependent or prerequisite PRs

Description Goployer now supports canary deployment. Documentation about this canary deployment will be updated soon

[codecov[bot]]

Codecov Report

Merging #115 into main will decrease coverage by 0.68%. The diff coverage is 1.90%.

@@           Coverage Diff            @@
##            main    #115      +/-   ##
========================================
- Coverage   5.99%   5.30%   -0.69%     
========================================
  Files         24      26       +2     
  Lines       3421    4374     +953     
========================================
+ Hits         205     232      +27     
- Misses      3205    4131     +926     
  Partials      11      11              

Impacted Files	Coverage Δ
pkg/aws/ec2.go	0.00% <0.00%> (ø)
pkg/aws/elbv2.go	0.00% <0.00%> (ø)
pkg/aws/ssm.go	0.00% <0.00%> (ø)
pkg/constants/constants.go	66.66% <ø> (ø)
pkg/deployer/bluegreen.go	4.50% <0.00%> (+2.90%)	:arrow_up:
pkg/helper/helper.go	0.00% <0.00%> (ø)
pkg/inspector/inspector.go	0.00% <0.00%> (ø)
pkg/runner/rurnner.go	4.77% <0.00%> (+0.40%)	:arrow_up:
pkg/deployer/canary.go	1.17% <1.17%> (ø)
pkg/deployer/deployer.go	2.01% <2.80%> (+2.01%)	:arrow_up:
... and 4 more

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[GwonsooLee]

Code review is done in private because there are too many lines changed. I will merge this and deploy Canary feature to experimental branch first, and after doing few more tests for few days, then this will be released