Interface for hardware temperature monitoring

[Barry Price]

I'd like to be able to snap an app that uses the /sys/class/hwmon tree for hardware temperature monitoring (which on my system at least actually contains symlinks to /sys/devices/virtual/hwmon), e.g.:

/snap/myapp/x1/lib/python2.7/site-packages/psutil/_pslinux.py:1160: RuntimeWarning: ignoring IOError(13, 'Permission denied') for file '/sys/class/hwmon/hwmon0/temp1_input'
  RuntimeWarning)
/snap/myapp/x1/lib/python2.7/site-packages/psutil/_pslinux.py:1160: RuntimeWarning: ignoring IOError(13, 'Permission denied') for file '/sys/class/hwmon/hwmon1/temp1_input'
  RuntimeWarning)
/snap/myapp/x1/lib/python2.7/site-packages/psutil/_pslinux.py:1160: RuntimeWarning: ignoring IOError(13, 'Permission denied') for file '/sys/class/hwmon/hwmon3/temp1_input'
  RuntimeWarning)
/snap/myapp/x1/lib/python2.7/site-packages/psutil/_pslinux.py:1160: RuntimeWarning: ignoring IOError(13, 'Permission denied') for file '/sys/class/hwmon/hwmon3/temp2_input'
  RuntimeWarning)
/snap/myapp/x1/lib/python2.7/site-packages/psutil/_pslinux.py:1160: RuntimeWarning: ignoring IOError(13, 'Permission denied') for file '/sys/class/hwmon/hwmon3/temp3_input'
  RuntimeWarning)
/snap/myapp/x1/lib/python2.7/site-packages/psutil/_pslinux.py:1160: RuntimeWarning: ignoring IOError(13, 'Permission denied') for file '/sys/class/hwmon/hwmon4/temp1_input'
  RuntimeWarning)

[Lucy Llewellyn (lucyllewy)]

This is provided by the `hardware-observe` plug.