Recommend that people use v2.0.0+ in the README
Recommend that people use v2.0.0+ in the README

Anything less than v2.0.0 is known to have some deficiencies, so this updates
the README to recommend consumers use 2.0.0+.

v2.0.0 needs to be released after merging this change.

Signed-off-by: Tim Heckman <8efd86fb78a56a5145ed7739dcb00c78581c5375@heckman.io>

gofrs/uuid,nanjj/uuid