Merge branch 'dev' of github.com:libigl/libigl into dev

Former-commit-id: 6802bb2a4ee60b3d566130db4493879b83ea4b9e

.appveyor.yml

@@ -8,6 +8,7 @@ branches:
     - alecjacobson
     - cmake
     - cgal
+    - dev
 environment:
   BOOST_ROOT: C:/Libraries/boost_1_65_1
 install: