Add work path CLI option (#6922)

Makes it possible to set the work path as a CLI option instead of
relying on environment variables which are somewhat opaque

integrations/integration_test.go

@@ -118,7 +118,7 @@ func initIntegrationTest() {
 		setting.CustomConf = giteaConf
 	}
 
-	setting.SetCustomPathAndConf("", "")
+	setting.SetCustomPathAndConf("", "", "")
 	setting.NewContext()
 	setting.CheckLFSVersion()
 	models.LoadConfigs()