fix: modules-download-mode support (#1593)

Author: ldez

.golangci.example.yml

@@ -51,7 +51,7 @@ run:
   # If invoked with -mod=vendor, the go command assumes that the vendor
   # directory holds the correct copies of dependencies and ignores
   # the dependency descriptions in go.mod.
-  modules-download-mode: readonly|release|vendor
+  modules-download-mode: readonly|vendor|mod
 
   # Allow multiple parallel golangci-lint instances running.
   # If false (default) - golangci-lint acquires file lock on start.

go.mod

@@ -70,7 +70,7 @@ require (
 	github.com/valyala/quicktemplate v1.6.3
 	golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634 // indirect
 	golang.org/x/text v0.3.4 // indirect
-	golang.org/x/tools v0.0.0-20210101214203-2dba1e4ea05c
+	golang.org/x/tools v0.0.0-20210105210202-9ed45478a130
 	gopkg.in/yaml.v2 v2.4.0
 	honnef.co/go/tools v0.0.1-2020.1.6
 	mvdan.cc/gofumpt v0.0.0-20201129102820-5c11c50e9475

go.sum

@@ -104,7 +104,7 @@ func (cl *ContextLoader) makeBuildFlags() ([]string, error) {
 	mod := cl.cfg.Run.ModulesDownloadMode
 	if mod != "" {
 		// go help modules
-		allowedMods := []string{"release", "readonly", "vendor"}
+		allowedMods := []string{"mod", "readonly", "vendor"}
 		var ok bool
 		for _, am := range allowedMods {
 			if am == mod {