Use scrutnizer on the CI process

.travis.coverage.sh

+set -x
+if [ "$TRAVIS_PHP_VERSION" = '7.1' ] ; then
+    wget https://scrutinizer-ci.com/ocular.phar
+    php ocular.phar code-coverage:upload --format=php-clover ./clover.xml
+fi

.travis.yml

@@ -112,6 +112,9 @@ matrix:
   allow_failures:
     - php: nightly
 
+after_script:
+  - sh .travis.coverage.sh
+
 install:
   - travis_retry composer install
 

README.md

@@ -3,6 +3,7 @@
 | [Master][Master] | [2.5][2.5] |
 |:----------------:|:----------:|
 | [![Build status][Master image]][Master] | [![Build status][2.5 image]][2.5] |
+| [![Code Coverage](https://scrutinizer-ci.com/g/doctrine/dbal/badges/coverage.png?b=master)](https://scrutinizer-ci.com/g/doctrine/dbal/?branch=master) | [![Code Coverage](https://scrutinizer-ci.com/g/doctrine/dbal/badges/coverage.png?b=2.5)](https://scrutinizer-ci.com/g/doctrine/dbal/?branch=2.5) |
 
 
 Powerful database abstraction layer with many features for database schema introspection, schema management and PDO abstraction.