NewClient initializing Bugsnag client.
Bugsnag client that automatic error sender to remote server.
We use this service to collect anonymous information
about the error and panic.
Service is activated if exist entry key = "error.sendremote"
and value = true in the database settings table.
Notify takes three arguments:
err - standard error;
sync - if true then the function waits for the end of sending;
skip - how many errors to remove from stacktrace.