typehints and imports

[mattsb42-aws]

Just wanted to let y'all know that you can remove stuff like this now that your minimum supported Python version is 3.7.

aws-dynamodb-encryption-python/src/dynamodb_encryption_sdk/structures.py

Lines 25 to 29 in e4dd5bf

	try: # Python 3.5.0 and 3.5.1 have incompatible typing modules
	from typing import Dict, Iterable, List, Optional, Set, Text # noqa pylint: disable=unused-import
	except ImportError: # pragma: no cover
	# We only actually need these imports when running the mypy checks
	pass

I put those in because the version of the typing library for specifically 3.5.0 and 3.5.1 only has a subset of the type definitions present for newer versions. Since the typehints are all in comments (another thing you can change now that you don't support 2.7 anymore), the imports were only necessary when running mypy, thus the except: pass rather than stubbing.

[khubaibalam2000]

Can I work on this issue?

[khubaibalam2000]

Resolved in #740.