Update rest-assured to v4.0.0

[chetanmeh]

Updates rest-assured library to v4.0.0 from v2.6.0 to enable execution on JDK 11

Description

Some of the tests were failing on JDK 11 which requires updating the rest-assured library to v4.0.0 as that has support for jdk 11

This PR is part of work being done under #4217 to enable JDK 11 support

Related issue and scope

• I opened an issue to propose and discuss this change (Update to Java 11 #4217)

My changes affect the following components

• API
• Controller
• Message Bus (e.g., Kafka)
• Loadbalancer
• Invoker
• Intrinsic actions (e.g., sequences, conductors)
• Data stores (e.g., CouchDB)
• Tests
• Deployment
• CLI
• General tooling
• Documentation

Types of changes

• Bug fix (generally a non-breaking change which closes an issue).
• Enhancement or new feature (adds new functionality).
• Breaking change (a bug fix or enhancement which changes existing behavior).

Checklist:

• I signed an Apache CLA.
• I reviewed the style guides and followed the recommendations (Travis CI will check :).
• I added tests to cover my changes.
• My changes require further changes to the documentation.
• I updated the documentation where necessary.

[markusthoemmes]

LGTM