Add instructions for running phpunit

tests/README.md

@@ -1,5 +1,9 @@
 # Plugin testing
 
+Plugin unit tests can be performed by running `phpunit` in the base plugin directory.
+
+### Creating plugin tests
+
 Plugins can be tested by creating a creating a file called `phpunit.xml` in the base directory with the following content, for example, in a file **/plugins/acme/blog/phpunit.xml**:
 
     <?xml version="1.0" encoding="UTF-8"?>
@@ -42,10 +46,11 @@ Then a **tests/** directory can be created to contain the test classes. The file
         }
     }
 
-The test class should extend the base class `PluginTestCase` and this is a special class that will set up the October database stored in memory, as part of the `setup()` method. It will also refresh the plugin being testing, along with any of the defined dependencies in the plugin registration file. This is the equivalent of running the following before each test:
+The test class should extend the base class `PluginTestCase` and this is a special class that will set up the October database stored in memory, as part of the `setUp()` method. It will also refresh the plugin being testing, along with any of the defined dependencies in the plugin registration file. This is the equivalent of running the following before each test:
 
     php artisan october:up
     php artisan plugin:refresh Acme.Blog
+    [php artisan plugin:refresh <dependency>, ...]
 
 # System testing