- Fail and log full SOAP response envelope as log if expected element
  not found
- Return installation id in response message from install job
- Wire up Sendgrid email support to run on Heroku
- Add instance_url to PackageInstallation
Add a generic 500 error page
- Added new force_sandbox option on a package.  If checked, a successful
  sandbox installation of the same package version must complete
successfully before a production upgrade is allowed
- Fixed bug in handling empty metadata lists in condition checks