Update develop.md

[rvanderwerf]

simulation jobs fail because setup script doesn't set iamRole arn in the roboMakerSettings.json file with a parameter validation error for the empty iamRole.

[ylukin]

There are two issues here:

• the install_deps.sh script does not correctly escape forward slashes in the role ARN when using sed to replace it in roboMakerSettings.json
• the initial bootstrap CloudFormation template does not export ROLE_ARN

See the the following PR I proposed to fix this: codingphun/aws_robomaker_jetbot_reinvent_workshop#3