Pynamodb

This is a backwards compatible, minor release.

Please read the [release notes](https://github.com/pynamodb/PynamoDB/blob/master/docs/release_notes.rst#v430) for a full list of changes.

This is a backwards compatible, minor release.

Please read the [release notes](https://github.com/pynamodb/PynamoDB/blob/master/docs/release_notes.rst#v420) for a full list of changes.

This is a backwards compatible, minor release.

* In the Model's Meta, you may now provide an AWS session token, which is mostly useful for assumed roles (700):
python
sts_client = boto3.client("sts")
role_object = sts_client.assume_role(RoleArn=role_arn, RoleSessionName="role_name", DurationSeconds=BOTO3_CLIENT_DURATION)
role_credentials = role_object["Credentials"]

class MyModel(Model):
class Meta:
table_name = "table_name"
aws_access_key_id = role_credentials["AccessKeyId"]
aws_secret_access_key = role_credentials["SecretAccessKey"]
aws_session_token = role_credentials["SessionToken"]

hash = UnicodeAttribute(hash_key=True)
range = UnicodeAttribute(range_key=True)

* Fix warning about inspect.getargspec (701)
* Fix provisioning GSIs when using pay-per-request billing (690)
* Suppress Python 3 exception chaining when "re-raising" botocore errors as PynamoDB model exceptions (705)

This is a major release with breaking changes.

Please read the [release notes](https://github.com/pynamodb/PynamoDB/blob/master/docs/release_notes.rst#v400) carefully for a full list of changes.

This is a beta release for a major release with breaking changes. Please read the release notes carefully and report any bugs encountered.

This is a beta release for a major release with breaking changes. Please read the release notes carefully and report any bugs encountered.