Check in the vendor directory

Travis seems to be having issues pulling deps, so we'll have to check in
the vendor directory and prevent the makefile from trying to regenerate
it normally.

vendor/github.com/mailru/easyjson/jlexer/bytestostr_nounsafe.go

@@ -0,0 +1,13 @@
+// This file is included to the build if any of the buildtags below
+// are defined. Refer to README notes for more details.
+
+//+build easyjson_nounsafe appengine
+
+package jlexer
+
+// bytesToStr creates a string normally from []byte
+//
+// Note that this method is roughly 1.5x slower than using the 'unsafe' method.
+func bytesToStr(data []byte) string {
+	return string(data)
+}