Use Go1.11 module (#5743)

* Migrate to go modules

* make vendor

* Update mvdan.cc/xurls

* make vendor

* Update code.gitea.io/git

* make fmt-check

* Update github.com/go-sql-driver/mysql

* make vendor

vendor/google.golang.org/appengine/internal/base/api_base.proto

@@ -0,0 +1,33 @@
+// Built-in base types for API calls. Primarily useful as return types.
+
+syntax = "proto2";
+option go_package = "base";
+
+package appengine.base;
+
+message StringProto {
+  required string value = 1;
+}
+
+message Integer32Proto {
+  required int32 value = 1;
+}
+
+message Integer64Proto {
+  required int64 value = 1;
+}
+
+message BoolProto {
+  required bool value = 1;
+}
+
+message DoubleProto {
+  required double value = 1;
+}
+
+message BytesProto {
+  required bytes value = 1 [ctype=CORD];
+}
+
+message VoidProto {
+}