Fix Beanstalk integ tests

[normj]

Description of changes:
The beanstalk tests deploying from existing environments are failing because existing environments were being created without permissions to download the deployment bundle from S3. This PR adds the managed beanstalk policy to the role that being created as part of the test.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 62.81%. Comparing base (9f812e9) to head (77a57ab).
Report is 1 commits behind head on dev.

Additional details and impacted files

@@             Coverage Diff             @@
##              dev     #886       +/-   ##
===========================================
+ Coverage   38.75%   62.81%   +24.06%     
===========================================
  Files         282      282               
  Lines       10922    10922               
  Branches     1517     1517               
===========================================
+ Hits         4233     6861     +2628     
+ Misses       6382     3523     -2859     
- Partials      307      538      +231     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.