fix websocket recursion error

[saikumar1607]

1. non-recursive based reconnect upon disconnects. The code changes in the PR detects the websocket disconnect automatically & reconnects after a delay. It makes sure only one websocket connection exists at any point of time. And no recursion stack.
2. removed appconfig_client.fetch_configurations() method which is of no use. Calling this method is causing regressions in the code. So it was better to remove it.
3. Calling the init & set_context methods are enough for the SDK to bootup & start evaluating the flags. No need to force fetch the configurations. The SDK would internally refresh the flag values based on socket updates received from server.
4. The release version is v0.4.0

[prajwal-jarali]

LGTM