Tweak CI config

.travis.yml

@@ -1,6 +1,12 @@
 language: rust
-sudo: false
-dist: trusty
+dist: xenial
+
+addons:
+  apt:
+    sources:
+      - ppa:chris-lea/redis-server
+    packages:
+      - redis-server
 
 services:
   - redis-server
@@ -25,12 +31,11 @@ matrix:
 env:
   global:
     # - RUSTFLAGS="-C link-dead-code"
-    - OPENSSL_VERSION=openssl-1.0.2
+    - OPENSSL_VERSION=openssl-1.1.1
 
 before_install:
-  - sudo add-apt-repository -y ppa:0k53d-karl-f830m/openssl
-  - sudo apt-get update -qq
-  - sudo apt-get install -qq libssl-dev libelf-dev libdw-dev cmake gcc binutils-dev libiberty-dev
+  - sudo apt-get -qq update
+  - sudo apt-get -y install libssl-dev libelf-dev libdw-dev binutils-dev libiberty-dev
 
 # Add clippy
 before_script: