Add version info in readme

Author: rajumsys

README.md

@@ -38,12 +38,13 @@ git clone git@github.com:SparkPost/wordpress-sparkpost.git ~/src/wordpress/wp-co
 * Activate the plugin from admin panel
 
 ## Running Tests
+* Make sure you're using PHP 5.6 or above.
 * Install test files by running `bash bin/install-wp-tests.sh wordpress_test root '' localhost latest`. Details on [wp-cli.org](http://wp-cli.org/docs/plugin-unit-tests/).
 * [Install composer](https://getcomposer.org/doc/00-intro.md)
-* Go to `./tests` directory
-* Run `composer install` to install required packages
-* To run tests, run `composer test`
-* Add you tests in `tests/specs` directory. Upon pushing the branch, Travis will automatically run it and generate reports (tests and coverage)
+* Go to `./tests` directory.
+* Run `composer install` to install required packages.
+* To run tests, run `composer test`.
+* Add your tests in `tests/specs` directory. Upon pushing the branch, Travis will automatically run it and generate reports (tests and coverage).
 
 ## Releasing