drop ghc-8.0 support and update Travis configuation

Author: int-e

.travis.yml

@@ -3,14 +3,14 @@ language: c
 
 matrix:
   include:
-    - env: CABALVER=1.24 GHCVER=8.0.2
-      addons: {apt: {packages: [cabal-install-1.24, ghc-8.0.2], sources: [hvr-ghc]}}
     - env: CABALVER=2.0  GHCVER=8.2.2
       addons: {apt: {packages: [cabal-install-2.0,  ghc-8.2.2], sources: [hvr-ghc]}}
     - env: CABALVER=2.2  GHCVER=8.4.3
       addons: {apt: {packages: [cabal-install-2.2,  ghc-8.4.3], sources: [hvr-ghc]}}
-    - env: CABALVER=2.2  GHCVER=8.4.3 CONFIG_OPTS=--enable-executable-dynamic
-      addons: {apt: {packages: [cabal-install-2.2,  ghc-8.4.3], sources: [hvr-ghc]}}
+    - env: CABALVER=2.4  GHCVER=8.6.1
+      addons: {apt: {packages: [cabal-install-2.4,  ghc-8.6.1], sources: [hvr-ghc]}}
+    - env: CABALVER=2.4  GHCVER=8.6.1 CONFIG_OPTS=--enable-executable-dynamic
+      addons: {apt: {packages: [cabal-install-2.4,  ghc-8.6.1], sources: [hvr-ghc]}}
 
 cache:
   directories:

hint.cabal

@@ -51,7 +51,7 @@ test-suite unit-tests
 
 library
   build-depends: base == 4.*,
-                 ghc >= 8.0 && < 8.8,
+                 ghc >= 8.2 && < 8.8,
                  ghc-paths,
                  ghc-boot,
                  mtl,

src/Hint/Typecheck.hs

@@ -65,11 +65,7 @@ normalizeType type_expr =
 
 -- add a bogus Maybe, in order to use it with mayFail
 exprType :: GHC.GhcMonad m => String -> m (Maybe GHC.Type)
-#if __GLASGOW_HASKELL__ < 802
-exprType = fmap Just . GHC.exprType
-#else
 exprType = fmap Just . GHC.exprType GHC.TM_Inst
-#endif
 
 -- add a bogus Maybe, in order to use it with mayFail
 typeKind :: GHC.GhcMonad m => String -> m (Maybe (GHC.Type, GHC.Kind))