updated many dependencies, ghc 8.x

Updated many dependencies, notably secret-sharing which dropped the dep on
polynomial, and so allows building with ghc 8.x.

Did not try to support building with older ghc because the semigroup-monid
transition would make it nontrivial.

Stackage lts-14.25 is a compromise, since the stack shipped in debian (even
unstable) is not able to handle newer ones.

This commit was sponsored by Eric Drechsel on Patreon.

2 files changed, 6 insertions, 4 deletions

diff --git a/Types/Cost.hs b/Types/Cost.hs
index 521d6c1..cd0a9f6 100644
--- a/Types/Cost.hs
+++ b/Types/Cost.hs
@@ -26,13 +26,15 @@ newtype Divisibility = Divisibility Integer
 data UsingHardware = UsingCPU | UsingGPU | UsingASIC
 	deriving (Show)
 
-instance Monoid (Cost t) where
-	mempty = CPUCost (Seconds 0) (Divisibility 1)
-	CPUCost (Seconds a) (Divisibility x) `mappend` CPUCost (Seconds b) (Divisibility y) =
+instance Semigroup (Cost t) where
+	CPUCost (Seconds a) (Divisibility x) <> CPUCost (Seconds b) (Divisibility y) =
 		-- Take maximum divisibility, to avoid over-estimating
 		-- the total cost.
 		CPUCost (Seconds (a+b)) (Divisibility $ max x y)
 
+instance Monoid (Cost t) where
+	mempty = CPUCost (Seconds 0) (Divisibility 1)
+
 -- | Operations whose cost can be measured.
 data DecryptionOp
 data CreationOp
diff --git a/Types/Storage.hs b/Types/Storage.hs
index c83593a..c145812 100644
--- a/Types/Storage.hs
+++ b/Types/Storage.hs
@@ -16,7 +16,7 @@ import Data.Aeson.Types
 -- | All known locations where shares can be stored, ordered with
 -- preferred locations first.
 newtype StorageLocations = StorageLocations [Storage]
-	deriving (Monoid)
+	deriving (Monoid, Semigroup)
 
 newtype LocalStorageDirectory = LocalStorageDirectory FilePath