Remove cachingLookups while initialising DnsSrvResolvers in BasicUsage class

[UdayHE]

When I tried to run BasicUsage class, it is throwing the exception"Session not supported with caching lookup" as expected.
So if we don't call the deprecated method cachingLookups in BasicUsage class while initialising DnsSrvResolvers, will solve this problem and helps to understand and debug the BasicUsage class. It helps who-ever cloning this repository and try to understand how this library works.

Example: