fix GolangCI issue (errcheck and could not determine GOARCH and Go compiler)

[po3rin]

I fix issue #3

GOLANGCI_COM_RUN=1 golangci-lint run --out-format=json --issues-exit-code=0 --deadline=5m --new=false --new-from-rev= --new-from-patch=
    server/main.go:13: Error return value of `http.ListenAndServe` is not checked (errcheck)

[po3rin]

next error

$ GOLANGCI_COM_RUN=1 golangci-lint run --out-format=json --issues-exit-code=0 --deadline=5m --new=false --new-from-rev= --new-from-patch=../changes.patch
    Running error: context loading failed: failed to load program with go/packages: could not determine GOARCH and Go compiler

[po3rin]

golangci/golangci-lint#761 (comment)