Constraint plutus to 1.37

Author: jasagredo

cabal.project

@@ -44,3 +44,9 @@ package ouroboros-network
 if(os(windows))
   constraints:
     bitvec -simd
+
+constraints:
+   -- There was a regression in 1.38 which was discarded for node 10.2. We don't
+   -- depend directly on plutus so we have to declare the bound here as a
+   -- constraint.
+   plutus ^>=1.37