update npm login method

pkg/plugin/publish/npm.go

@@ -6,11 +6,11 @@ import (
     "github.com/drone/drone/pkg/build/buildfile"
 )
 
+// use npm trick instead of running npm adduser that requires stdin
 var npmLoginCmd = `
-npm login <<EOF
-%s
-%s
-%s
+cat <<EOF > ~/.npmrc
+_auth = $(echo "%s:%s" | tr -d "\r\n" | base64)
+email = %s
 EOF
 `
 

pkg/plugin/publish/npm_test.go

@@ -59,10 +59,6 @@ func TestNPMPublish(t *testing.T) {
         t.Fatalf("Can't unmarshal publish script: %s", err)
     }
 
-    if !strings.Contains(bscr, "npm login") {
-        t.Error("Expect script to contain login command")
-    }
-
     if !strings.Contains(bscr, "npm publish") {
         t.Error("Expect script to contain install command")
     }