switch to Travis CI containers

.travis.yml

@@ -4,9 +4,7 @@ perl:
   - "5.18"
   - "5.16"
   - "5.14"
-# Can't use containers until this is accepted:
-# https://github.com/travis-ci/apt-package-whitelist/issues/1759
-#sudo: false
+sudo: false
 addons:
   apt:
     packages:
@@ -14,8 +12,6 @@ addons:
     - texlive
     - texi2html
 before_install:
-  - sudo apt-get update -qq
-  - sudo apt-get install -qq texi2html
   - autoreconf --install
   - eval `perl -V:siteprefix`
   - ./configure --prefix=$siteprefix && make