pin aws-sigv4 and aws-sdk-core

Change-Id: Ifb9c228c111886e90a6e78d5febef98abbd0780c
Reviewed-on: https://gerrit.instructure.com/155748


Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>
QA-Review: James Williams  <jamesw@instructure.com>
Tested-by: James Williams <jamesw@instructure.com>

Gemfile.d/app.rb

@@ -50,6 +50,9 @@ gem "aws-sdk-kinesis", '1.2.0', require: false
 gem "aws-sdk-s3", '1.8.2', require: false
 gem "aws-sdk-sns", '1.1.0', require: false
 gem "aws-sdk-sqs", '1.3.0', require: false
+gem "aws-sdk-core", "3.22.0", require: false
+gem "aws-sigv4", "1.0.2", require: false
+
 gem 'barby', '0.6.5', require: false
   gem 'rqrcode', '0.10.1', require: false
   gem 'chunky_png', '1.3.10', require: false