Fix import of excaptions in apicli (#284)

- Some exceptions could not be imported so changing the import to
``librouteros.exceptions```.
- The ```ConnectionError``` is a build-in exception from Python

apicli.py

@@ -11,7 +11,8 @@
 from select import select
 from os import linesep
 
-from librouteros import connect, ConnectionError, TrapError, FatalError
+from librouteros import connect
+from librouteros.exceptions import TrapError, FatalError
 
 argParser = ArgumentParser(description='mikrotik api cli interface')
 argParser.add_argument(