TravisCI config update

Author: eblount

.travis.yml

@@ -1,13 +1,21 @@
 language: php
 
 php:
-  - 5.4
   - 5.5
   - 5.6
-  - hhvm
+  - 7.0
+
+env:
+  matrix:
+    - COMPOSER_FLAGS="--prefer-lowest"
+    - COMPOSER_FLAGS=""
 
 before_script:
   - travis_retry composer self-update
-  - travis_retry composer install --prefer-source --no-interaction --dev
+  - travis_retry composer install ${COMPOSER_FLAGS} --no-interaction --prefer-source
+
+script:
+  - phpunit --coverage-text --coverage-clover=coverage.clover
 
-script: phpunit
+after_script:
+  - php vendor/bin/ocular code-coverage:upload --format=php-clover coverage.clover