Simple Travis configuration to prevent warnings.

- No PHPUnit here; the necessary fixes to make tests pass in Travis are made in VuFind 2.5.

.travis.yml

+language: php
+php:
+  - 5.4
+
+env:
+  - VUFIND_HOME=$PWD VUFIND_LOCAL_DIR=$PWD/local
+
+before_script:
+  - pear install pear/PHP_CodeSniffer
+  - phpenv rehash
+
+script:
+  - phpcs --standard=PEAR --ignore=*/config/*,*/tests/* --extensions=php $PWD/module
+