Merge branch 'pr91'

Author: clue

.travis.yml

@@ -8,4 +8,4 @@ php:
 before_script:
   - composer install --dev --prefer-source --no-interaction
 script:
-  - phpunit --coverage-text
+  - php vendor/bin/phpunit --coverage-text

README.md

@@ -93,10 +93,15 @@ users should install from [GraphViz homepage](http://www.graphviz.org/Download.p
 
 ## Tests
 
-To run the test suite, you need PHPUnit. Go to the project root and run:
-````
-$ phpunit
-````
+This library uses phpunit for its extensive testsuite.
+You can either use a global installation or rely on the one composer installs
+when you first run `$ composer install`.
+This sets up the developer environment, so that you
+can now run it from the project root directory:
+
+```bash
+$ php vendor/bin/phpunit`
+```
 
 ## Contributing