Attempt fix travis build

.travis.yml

@@ -0,0 +1,31 @@
+dist: xenial
+sudo: required
+language: c++
+matrix:
+  include:
+    - env: {MATRIX_EVAL: '"CC=gcc-7 && CXX=g++-7 && alias g++=g++-7"'}
+      addons:
+        apt:
+          update: true
+          sources:
+            - ubuntu-toolchain-r-test
+          packages:
+            - libxdo-dev
+            - libinput-tools
+            - g++-7
+    - env: {MATRIX_EVAL: '"CC=gcc-8 && CXX=g++-8 && alias g++=g+++-8"'}
+      addons:
+        apt:
+          update: true
+          sources:
+            - ubuntu-toolchain-r-test
+          packages:
+            - libxdo-dev
+            - libinput-tools
+            - g++-8
+before_install:
+  - eval "${MATRIX_EVAL}"
+  - g++ --version
+install: bash install
+script: bash tests/run_tests
+after_script: bash uninstall