Pinned Click to <8.0 on py27,34,35
Pinned Click to <8.0 on py27,34,35

Details:

* Click starting with version 7.0 properly declares its supported Python
  versions. Click 7.0 dropped support for for Python 3.4, but for unknown
  reasons pip installs it on Python 3.4 and it works there. zhmccli requires
  the functionality of Click 7.

  Click 8.0 will drop support for Python 2.7,3.5 but it is not released yet.

  This fix pins the versions of Click to <8.0 for Python <3.6, as a forward
  looking measure.

Signed-off-by: Andreas Maier <38dbb04957d222ea6ce72de72413b1e55e665472@de.ibm.com>

zhmcclient/zhmccli