Init web socket clients lazily

[mykola-mokhnach]

Change list

It looks like web socket lib throws an exception on init for some reason. So it would be safer to init the stuff lazily in order to avoid the java class loader from throwing this exception each time when the driver is instantiated.

See https://stackoverflow.com/questions/50293463/appium-test-case-throws-exception for the reference.

Types of changes

• No changes in production code.
• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)