fixed: support ghc-8.8.2 and lts-15.2

.travis.yml

@@ -1,15 +1,23 @@
 sudo: false
+dist: bionic
+language: generic
+
 addons:
   apt:
-    sources:
-        - hvr-ghc
     packages:
-        - libgmp-dev
-        - ghc-8.0.1
-        - cabal-install-1.24
+      - libgmp-dev
+
+before_install:
+  - unset CC
+  # workaround Disallowing sources: hvr-ghc
+  - sudo add-apt-repository ppa:hvr/ghc -y
+  - sudo apt-get update -q
+  - sudo apt-get install ghc-8.8.3 cabal-install-2.4 -y
+  - export PATH="$HOME/.cabal/bin:/opt/ghc/bin:/opt/cabal/bin:$PATH"
+
 install:
-        - export PATH=/opt/cabal/1.24/bin:/opt/ghc/8.0.1/bin:$PATH
-        - travis_retry cabal update
-        - cabal install --only-dependencies -fexamples --enable-tests
+  - travis_retry cabal update
+  - cabal install --only-dependencies -fexamples --enable-tests
+
 script:
-        - cabal configure -fexamples --enable-tests && cabal build
+  - cabal configure -fexamples --enable-tests && cabal build

aws.cabal

@@ -169,7 +169,7 @@ Library
     Build-depends: network == 3.*, network-bsd == 2.8.*
   else
     Build-depends: network == 2.*
- 
+
   if !impl(ghc >= 7.6)
     Build-depends: ghc-prim
 

stack.yaml

@@ -15,7 +15,7 @@
 # resolver:
 #  name: custom-snapshot
 #  location: "./custom-snapshot.yaml"
-resolver: lts-11.9
+resolver: lts-15.2
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.