Update requirements and test setup.

Created by: NotSpecial

For some reason, the generic alpine image would not correctly update the repositories and would not find mongodb.

With a fixed version, this issue does not occur anymore.

Additionally, important changes due to version update:

• Pytz: Dependency removed, as datetime can handle utc on its own.

• Cerberus: valueschema renamed to valuesrules.

• MongoDB: insert is replaced by insert_one and insert_many. As a consequence, ObjectIDs are retrieved a bit differently.

• PassLib: encrypt renamed to hash. vary_round is deprecated, has it "provided little security and was not worth the additional complexity" 1.

Closes #394 (closed) (new eve version fixes this bug)