evolve: specify the 'minimalhgversion'
3.7 added a new nice and shinny variable to help user know when they use the
wrong version of Mercurial with an extension. We now use it.
--- a/hgext3rd/evolve/__init__.py Tue Mar 07 12:27:01 2017 +0100
+++ b/hgext3rd/evolve/__init__.py Tue Mar 07 13:12:27 2017 +0100
@@ -19,6 +19,7 @@
"""
__version__ = '5.6.0'
testedwith = '3.8.4 3.9.2 4.0.2 4.1'
+minimumhgversion = '3.8'
buglink = 'https://bz.mercurial-scm.org/'