Add Ubuntu 14.04 LTS (Trusty Tahr) jobs for those that can use it

.travis.yml

@@ -1,4 +1,5 @@
 dist: xenial
+sudo: required
 language: python
 cache: pip
 
@@ -16,11 +17,19 @@ matrix:
       dist: trusty
     - python: "pypy3"
       dist: trusty
-    - python: '3.7-dev'
+    - python: '3.7'
     - python: '2.7'
+    - python: '2.7'
+      dist: trusty
     - python:  "2.7_with_system_site_packages" # For PyQt4
+    - python:  "2.7_with_system_site_packages" # For PyQt4
+      dist: trusty
     - python: '3.6'
+    - python: '3.6'
+      dist: trusty
     - python: '3.5'
+    - python: '3.5'
+      dist: trusty
     - python: '3.4'
       dist: trusty
     - env: DOCKER="alpine" DOCKER_TAG="pytest"
@@ -35,8 +44,6 @@ matrix:
     - env: DOCKER="fedora-26-amd64" DOCKER_TAG="pytest"
     - env: DOCKER="fedora-27-amd64" DOCKER_TAG="pytest"
 
-sudo: required
-
 services:
   - docker