v0.37.2.
Fixed test code for multiple execution of callback with multiple
unsubscriptions.
Update Libra to v0.16.0, removed error for unsubscribe command when
the client is not already in Pubsub mode.
On branch master
modified:   Readme.md
modified:   package.json
modified:   test/pubsub-mode-off-unsubscribe-test.js