text: Title: high CPU rPi 3B
  Body: ## Mycodo Issue Report:
   Mycodo Version: 7.5.8 
  Python Version: 3.5.3 (default, Sep 27 2018, 17:25:39) [GCC 6.3.0 20170516] 
  Database Version: 6333b0832b3d
  Daemon Status: Running 
  Daemon Process ID: 1108 
  Daemon RAM Usage: 110.196 MB 
  Daemon Virtualenv: Yes 
  Frontend RAM Usage: 54.984 MB 
  Frontend Virtualenv: Yes
  #### Problem Description
  High CPU usage slow response to commands
   
  ### Errors
    2019-06-13 21:22:07,639 - ERROR - mycodo.daemon - Could not query output state: 'NoneType' object has no attribute 'output_state'
  2019-06-13 21:22:11,112 - ERROR - mycodo.daemon - Could not find Output Controller
  2019-06-13 21:33:47,277 - ERROR - mycodo.daemon - Could not query output state: You must setup() the GPIO channel first
  2019-06-13 21:33:47,714 - ERROR - mycodo.daemon - Could not query output state: You must setup() the GPIO channel first
  2019-06-13 21:33:50,264 - ERROR - mycodo.daemon - Could not query output state: You must setup() the GPIO channel first
  2019-06-13 21:57:35,184 - ERROR - mycodo.daemon - Could not query output state: 'NoneType' object has no attribute 'output_state'
  2019-06-13 21:57:44,772 - ERROR - mycodo.daemon - Could not query output state: 'NoneType' object has no attribute 'output_state'
  2019-06-13 21:57:45,880 - ERROR - mycodo.daemon - Could not query output state: 'NoneType' object has no attribute 'output_state'
  2019-06-13 21:57:46,894 - ERROR - mycodo.daemon - Could not query output state: 'NoneType' object has no attribute 'output_state'
  2019-06-13 21:57:53,029 - ERROR - mycodo.daemon - Could not query output state: 'NoneType' object has no attribute 'output_state'
  2019-06-13 21:58:41,684 - ERROR - mycodo.daemon - Could not query output state: 'NoneType' object has no attribute 'output_state
  
  htop screenshot:
  ![image](https://user-images.githubusercontent.com/22091149/59547260-e6622e00-8ef0-11e9-8e48-ee75d58ffeab.png)
  Controls using high cpu are GPIO hardwired controls that seem to  physically work ok but generating daemon errors.
  
  