Incorrect constants generation on GlassMapper.csx

[blipson89]

https://github.com/blipson89/Leprechaun/blob/2a3d7f45f0243655558b481e80052118da86d05e/src/Leprechaun.CodeGen.Roslyn/Scripts/GlassMapper.csx#L139

public const string {field.CodeName}FieldName = ""{field.Name}"";");