Merge branch 'gh-pages'
add api reference
Moved the logic of placing a document in a collection of Document in the Collection#add. Add Collection#updateIdLink()
fixed bugs for 3.8.16
The recovered population in the arrays in the fields of the sub-document and Not writable identical arrays
clean up
Add approximatelyEqual (toObject({depopulate: 1}), not compare subdoc._id) To the array of sub-documents did not depopulate when set(). Изменён ObjectId.prototype.cast Not to depopulate when set(). Improved utils.deepEqual()
clean up
update readme
add codeclimate coverage
update Readme (add coverage)
config CODECLIMATE
update gitignore and config coverage
config CODECLIMATE
config code climate
config code climate
config code climate
config code climate
config code climate
clean up