Update Dockerfile
Update Dockerfile

Encountered error in second step of Dockerfile. Used the following to rectify the issue: https://superuser.com/questions/1423486/issue-with-fetching-http-deb-debian-org-debian-dists-jessie-updates-inrelease?newreg=ebb41cc90fe14d52a0e83393a2a90918

OperationCode/operationcode_backend,OperationCode/operationcode_backend,OperationCode/operationcode_backend