0.7.0

[hakancelikdev]

• Implement array field #63
• Using objects is really necessary? #62
• Use open's flag to separate readers and writers, handler multiple ops at a same time #61
• Use dbm.whichdb to set file extension #60
• The id does not need to be registered in the database header. #57
• id field can not overwrite or change type #55
• Implement optional none case #65