This patch fixes the below bug by properly checking the old and new
version specifiers:
It seems that packaging fixed its SpecifierSet class' 'contains'
method recently which brought out a bug in validator:
When checking minimum versions we get a false negative [1] result due
to comparing '<str>' in '<SpecifierSet>', like '2.1.0' version string
(from old '>2.1.0' specifier) in '>2.1.0' (new) specifier, which should
be equal, but clearly version 2.1.0 is not in range >2.1.0, hence
the comparison gives back an error.
[1] Changed supported versions for dependency pyparsing from >2.1.0 to >2.1.0 without at least incrementing minor number
Change-Id: Iac1691714eaa8f5c236ed4c79b8ea7be92b8fcd9
707a514d69