1.2.0

• The database decoder now does bound checking when decoding data from the database. This is to help ensure that the reader does not panic when given a corrupt database to decode. Closes #37.
• The reader will now return an error on a data structure with a depth greater than 512. This is done to prevent the possibility of a stack overflow on a cyclic data structure in a corrupt database. This matches the maximum depth allowed by libmaxminddb. All MaxMind databases currently have a depth of less than five.