Add travis ci support.

.travis.yml

@@ -0,0 +1,40 @@
+language: emacs-lisp
+sudo: false
+
+addons:
+  apt:
+    packages:
+      - libxpm-dev
+      - libgif-dev
+      - libpng-dev
+      - libjpeg-dev
+      - libtiff4-dev
+      - libacl1-dev
+
+env:
+  global:
+    - PATH="$HOME/bin:$PATH"
+  matrix:
+    - EMACS_VERSION=25.1
+    - EMACS_VERSION=26.1
+    - EMACS_VERSION=snapshot
+
+matrix:
+  fast_failure: true
+  allow_failures:
+    - env: EMACS_VERSION=snapshot
+
+before_install:
+  - "export DISPLAY=:99.0"
+  - "sh -e /etc/init.d/xvfb start"
+  - sleep 3
+  - wget 'https://raw.githubusercontent.com/flycheck/emacs-travis/master/emacs-travis.mk'
+  - make -f emacs-travis.mk install_texinfo
+  - make -f emacs-travis.mk EMACSCONFFLAGS="" install_emacs
+  - make -f emacs-travis.mk install_cask
+
+install:
+  - cask install
+
+script:
+  - cask exec ert-runner --win