3.10.0

• Bump version
• Test that {x: {$in: [None,..]}} matches when {x: {$exists: False}}
• Make {x: {$in: [None,...}} match if {x: {$exists: False}}
• test
• allow caller to pass generators to insert_many()
• Improve conditional imports in helpers.py
• Fix datetime millisecond resolution according to MongoDB capabilities
• Correct conditional import in helpors.py
• Add support to tz_aware=True option
• fixing pep8 issues
• added collation as an attribute to the Cursor object