Server methods that return false either synchronously or asynchronously are not handled correctly

[cmerchant]

Calling a server method that resolves with a promise that returns a false or a synchronous method that returns false results in unexpected problems. The client does not get the expected false result and instead gets undefined or an unhandled exception. I have created a two unit tests in this project that show the issues. Basically the error we are seeing is,

1. Client #call should support asynchronous server methods returning boolean false:
   AssertionError: expected undefined to exist

Or in the synchronous case,

(node:3916) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 5): TypeError: result.then is not a function
(node:3916) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

See branch falseFix with failing unit test for details.

Pull request submitted

[brozeph]

Resolved in PR #6 - closing as fixed