Update version identifier to 1.7.1

Author: farleyb-amazon

src/aws_encryption_sdk/identifiers.py

@@ -27,7 +27,7 @@
     # We only actually need these imports when running the mypy checks
     pass
 
-__version__ = "1.7.0"
+__version__ = "1.7.1"
 USER_AGENT_SUFFIX = "AwsEncryptionSdkPython/{}".format(__version__)