Undefined name: import sys for line 91
Undefined name: import sys for line 91

[flake8](http://flake8.pycqa.org) testing of https://github.com/home-assistant/appdaemon on Python 3.7.1

$ __flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics__
```
./conf/example_apps/sound.py:90:18: F821 undefined name 'sys'
        self.log(sys.exc_info())
                 ^
./conf/example_apps/alexa.py:11:18: F821 undefined name 'get_alexa_intent'
        intent = get_alexa_intent(data)
                 ^
./conf/example_apps/alexa.py:14:57: F821 undefined name 'get_alexa_error'
            self.log("Alexa err encountered: {}".format(get_alexa_error(data)))
                                                        ^
./conf/example_apps/alexa.py:36:16: F821 undefined name 'get_alexa_slot_value'
        user = get_alexa_slot_value(data, "User")
               ^
./conf/example_apps/occusim.py:77:64: F821 undefined name 'i'
          self.log("step_{} end < start - ignoring end".format(i))
                                                               ^
./conf/example_apps/occusim.py:120:70: F821 undefined name 'i'
                self.log("step_{} end < start - ignoring end".format(i))
                                                                     ^
6     F821 undefined name 'get_alexa_intent'
6
```
acockburn/appdaemon,acockburn/appdaemon