[PATCH 1 of 4] pytest: restrict to 3.7.0 to avoid regression in 3.7.1

[Mads Kiilerich]

On 08/30/2018 10:42 PM, Thomas De Schampheleire wrote:
> # HG changeset patch
> # User Thomas De Schampheleire <thomas.de_schampheleire at nokia.com>
> # Date 1535660955 -7200
> #      Thu Aug 30 22:29:15 2018 +0200
> # Node ID ad3cc6e18d57c36c56334476f2a92da19cdf4739
> # Parent  61bd3efe4a6c2f68e88313d0aa237188145fa558
> pytest: restrict to 3.7.0 to avoid regression in 3.7.1

Do you agree 
https://bitbucket.org/kiilerix/kallithea/commits/897fb0c7cd065b2da2a767b4bc59ece3a07a7c93 
could be a better alternative?

It seems like class fixtures only worked by coincidence and probably not 
will be fixed.

/Mads