MM-10769 Rename references to spf13/viper to mattermost/viper (#8948)

Gopkg.lock

@@ -468,7 +468,7 @@
 
 [[projects]]
   branch = "env-settings"
-  name = "github.com/spf13/viper"
+  name = "github.com/mattermost/viper"
   packages = ["."]
   revision = "4f5003aa93559718c866d86fbc795439079484f5"
   source = "https://github.com/mattermost/viper"

Gopkg.toml

@@ -46,7 +46,7 @@
 
 # Fork for adding our own method to viper EnvSettings
 [[constraint]]
-  name = "github.com/spf13/viper"
+  name = "github.com/mattermost/viper"
   source = "https://github.com/mattermost/viper"
   branch = "env-settings"
 

utils/config.go

@@ -16,8 +16,8 @@ import (
 	"strings"
 
 	"github.com/fsnotify/fsnotify"
+	"github.com/mattermost/viper"
 	"github.com/pkg/errors"
-	"github.com/spf13/viper"
 
 	"net/http"