Added changes suggested by goimports

[brunats]

- What I did
Hi Ritchiers,

In the search for improving the quality of the code I decided to open a PR by passing the goimports in the project.

Adds all suggested changes (and revised one by one) to the project.

- How to verify it

Clone this pr with the command

git fetch upstream pull/509/head:improvement/updates-linters

And run goimports

git checkout master
goimports -w $(find . -type f -name '*.go' -not -path "./vendor/*") # Check the differences generated
git checkout improvement/updates-linters
goimports -w $(find . -type f -name '*.go' -not -path "./vendor/*") # Check the differences

- Description for the changelog

Improves code quality related to linter goimport.

[codecov-commenter]

Codecov Report

Merging #509 into master will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #509      +/-   ##
==========================================
+ Coverage   76.27%   76.31%   +0.04%     
==========================================
  Files          95       95              
  Lines        3199     3205       +6     
==========================================
+ Hits         2440     2446       +6     
  Misses        593      593              
  Partials      166      166              

Impacted Files	Coverage Δ
pkg/credential/credential.go	0.00% <ø> (ø)
pkg/formula/builder/bat.go	0.00% <ø> (ø)
pkg/formula/formula.go	90.90% <ø> (ø)
pkg/metric/checker.go	100.00% <ø> (ø)
pkg/metric/user_id_generator.go	63.63% <ø> (ø)
pkg/rcontext/remover.go	68.42% <ø> (ø)
pkg/upgrade/url_finder.go	100.00% <ø> (ø)
pkg/cmd/set_context.go	48.64% <100.00%> (ø)
pkg/cmd/upgrade.go	100.00% <100.00%> (ø)
pkg/formula/runner/inputs.go	98.18% <100.00%> (+0.06%)	⬆️

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[victor-schumacher]

🥇

[victor-schumacher]

nice

[lucasdittrichzup]

🚀

[brunasilvazup]

/merge qa

[ritchie-bot]

👌 Merged branch improvement/updates-linters into qa