Add golangci-lint

[AlekSi]

Closes #162.

[AlekSi]

Waiting for those issues to be resolved:

• uname_os_check 'MSYS_NT-10.0' got converted to 'msys_nt-10.0' which is not a GOOS value client9/shlib#13
• Update README.txt with instructions for how to install on Windows golangci/golangci-lint#338
• https://github.com/goreleaser/goreleaser/issues/933

[codecov]

Codecov Report

Merging #192 into v1-stable will decrease coverage by 2.55%.
The diff coverage is n/a.

@@              Coverage Diff              @@
##           v1-stable     #192      +/-   ##
=============================================
- Coverage      68.49%   65.94%   -2.56%     
=============================================
  Files             19       19              
  Lines           1565     1565              
=============================================
- Hits            1072     1032      -40     
- Misses           443      480      +37     
- Partials          50       53       +3

Impacted Files	Coverage Δ
reform-db/cmd_init_mssql.go	0% <0%> (-34.49%)	⬇️
reform-db/cmd_init_mysql.go	0% <0%> (-32.26%)	⬇️
reform-db/models.go	64.7% <0%> (-11.77%)	⬇️
reform-db/cmd_init.go	62.35% <0%> (-7.06%)	⬇️
querier_selects.go	94.78% <0%> (-2.61%)	⬇️
querier_commands.go	80.8% <0%> (-0.93%)	⬇️

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