Move lexer one level up, we'll use this level for lexer and parser both.

gql/lexer/lexer.go → gql/lexer.go

-package gqlex
+package gql
 
 import (
 	"fmt"

gql/lexer/lexer_test.go → gql/lexer_test.go

-package gqlex
+package gql
 
 import (
 	"fmt"

gql/lexer/state.go → gql/state.go

-package gqlex
+package gql
 
 const (
 	leftCurl  = '{'