aws-s3: Tells that provider is s3 and to load data from s3.
(): Parameters for aws-s3. Currently, a single paramater is accepted:
region: region for aws-s3. If this is not set, secretsfoundry looks for AWS_REGION environment variable. If both aren't set, you can make AWS look for the default region defined in ~/.aws/config by setting the environment variable AWS_SDK_LOAD_CONFIG=1
bucket: Name of the bucket to be used. Must follow the REGEX /^[\w/-._]+$/
key: The key used for fetching the object details. Must follow the REGEX /^[\w]+?/