Release v2.0.0

Changes since v1.0.0
--------------------
6fce163 Update lein to v2.9.8
b4443e9 Upgrade to protojure v2.0
9f1637e Run lein-ancient and update cljfmt errors discovered
24e5941 Update circle config (#60)

Signed-off-by: Greg Haskins <greg@manetu.com>