Try to add coverity

.travis.yml

@@ -1,7 +1,22 @@
+
 sudo: required
 dist: trusty
 language: c
+env:
+  global:
+   # The next declaration is the encrypted COVERITY_SCAN_TOKEN, created
+   #   via the "travis encrypt" command using the project repo's public key
+   - secure: "Uodrn3x36plX2yk4+c7eimCuv7j6p6n1XCNbNEYxibRX77730eQMCVS0BvM40OgD7m5K9s2hIQaMV7EMj3qKuRmemULDVJVTgNd1fbx6t4BhYh+Hrf6FhsNcm9nFxvQQrdJAVSOwIAlrUilVFotDRt9qKqLwwZiBKIs5gBPcHQY="
+
 addons:
+    coverity_scan:
+      project:
+        name: "DaveDavenport/rofi"
+        description: "Build submitted via Travis CI"
+      notification_email: qball@gmpclient.org
+      build_command_prepend: "./configure; make clean"
+      build_command:   "make -j 4"
+      branch_pattern: coverity_scan
     apt:
         packages:
             - autoconf
@@ -28,6 +43,8 @@ compiler:
 before_install:
     - sudo add-apt-repository -y 'deb http://debian.jpleau.ca/ jessie-backports main contrib non-free'
     - sudo apt-get update -qq
+    - echo -n | openssl s_client -connect scan.coverity.com:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | sudo tee -a /etc/ssl/certs/ca-
+
 
 # TODO: We install xkbcommon here, until Travis use an up-to-date enough Ubuntu
 # TODO: We install libxcb-ewmh-dev here, until it is whitelisted again in Travis
@@ -55,3 +72,4 @@ script:
 
 after_success:
       - bash <(curl -s https://codecov.io/bash)
+