Remove Travis CI config

.travis.yml

@@ -1,21 +0,0 @@
-# Disable Docker stuff to try to make it faster
-sudo: true
-dist: bionic
-
-# Choose a lightweight base image; we provide our own build tools.
-language: generic
-
-# GHC depends on GMP. You can add other dependencies here as well.
-addons:
-  apt:
-    packages:
-    - libgmp-dev
-
-# Edit etc/ci-script.sh to change GHC version
-script:
-- ./etc/check.sh
-
-cache:
-  directories:
-    - $HOME/.stack
-    - $HOME/.stackage/curator/cache