Add new packages chemical-equation, zip2tar

Author: thielema

build-constraints.yaml

@@ -618,6 +618,7 @@ packages:
         - cabal-sort
         - calendar-recycling
         - checksum
+        - chemical-equation
         - coinor-clp
         - combinatorial
         - comfort-graph
@@ -700,6 +701,7 @@ packages:
         - wraxml
         - xml-basic
         - youtube
+        - zip2tar
         - prelude-compat
         - fft
         - carray