Merge branch 'pr/221' into devel

* pr/221:
  Step up distros to Xenial + Trusty

.travis.yml

@@ -13,21 +13,21 @@ env:
 matrix:
   include:
     - os: linux
-      dist: precise
+      dist: trusty
     # 64-bit builds
     - os: linux
-      dist: trusty
+      dist: xenial
       env:
         - TEST_BUILDS=1
     # 32-bit builds
     - os: linux
-      dist: trusty
+      dist: xenial
       env:
         - TEST_BUILDS=1
         - PLAT=i686
     # Builds with caching
     - os: linux
-      dist: trusty
+      dist: xenial
       env:
         - TEST_BUILDS=1
         - USE_CCACHE=1

README.rst

@@ -209,8 +209,10 @@ To use these scripts
 
     # Required in Linux to invoke `docker' ourselves
     services: docker
-    # A newer distro will also do
-    dist: trusty
+
+    # Host distribution.  This is the distribution from which we run the build
+    # and test containers, via docker.
+    dist: xenial
 
     matrix:
       include: