compatibility with mtl-2.3

src/Brick/Main.hs

@@ -54,6 +54,7 @@ where
 
 import qualified Control.Exception as E
 import Lens.Micro ((^.), (&), (.~), (%~), _1, _2)
+import Control.Monad
 import Control.Monad.State.Strict
 import Control.Monad.Reader
 import Control.Concurrent (forkIO, killThread)

src/Brick/Widgets/Core.hs

@@ -122,6 +122,7 @@ import Data.Monoid ((<>))
 
 import Lens.Micro ((^.), (.~), (&), (%~), to, _1, _2, each, to, Lens')
 import Lens.Micro.Mtl (use, (%=))
+import Control.Monad
 import Control.Monad.State.Strict
 import Control.Monad.Reader
 import qualified Data.Foldable as F

src/Brick/Widgets/Internal.hs

@@ -10,6 +10,7 @@ where
 
 import Lens.Micro ((^.), (&), (%~))
 import Lens.Micro.Mtl ((%=))
+import Control.Monad
 import Control.Monad.State.Strict
 import Control.Monad.Reader
 import Data.Maybe (fromMaybe, mapMaybe)