gometalinter -> golangci-lint migration (#3933)

{,scripts/}Makefile:
- Remove gometalinter, install golangci-lint.
- Remove distinction between tools and devtools.
  Just tools is enough.
- test_lint -> lint
  Migrating away from underscore separated names.
- Remove unnecessary targets.
- Drop tendermint/lint. Incompatbile with golangci-lint
  and no longer necessary anyway.
- Fix misleading message in go-mod-cache.
- New ci-target to avoid download tools twice.
- Run tests with -mod=readonly.

Port tools/gometalinter.json to .golangci.yml
Update CircleCI config accordingly.

Closes: #3896

client/utils/utils.go

@@ -3,10 +3,11 @@ package utils
 import (
 	"bytes"
 	"fmt"
-	"github.com/spf13/viper"
 	"io/ioutil"
 	"os"
 
+	"github.com/spf13/viper"
+
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/codec"
 
@@ -102,7 +103,7 @@ func CompleteAndBroadcastTxCLI(txBldr authtxb.TxBuilder, cliCtx context.CLIConte
 
 	// broadcast to a Tendermint node
 	res, err := cliCtx.BroadcastTx(txBytes)
-	cliCtx.PrintOutput(res)
+	cliCtx.PrintOutput(res) // nolint:errcheck
 	return err
 }