Clarify PHP versions (#96)

* Clarify PHP versions

* Fix typo

README.md

@@ -28,8 +28,7 @@ Framework agnostic virtual PHP development environment.
 ## What do you get?
 
 A 64-bit virtual machine running [Ubuntu 16.04 LTS](https://wiki.ubuntu.com/LTS)
-with a lot of useful [software and features](http://cakebox.readthedocs.org/en/latest/features/)
-like PHP 7.1.
+with a lot of useful [software and features](http://cakebox.readthedocs.org/en/latest/features/).
 
 ## Installation
 
@@ -41,6 +40,8 @@ vagrant plugin install vagrant-vbguest
 vagrant up
 ```
 
+Installed by default: PHP 5.6
+
 Optionally upgrade your box to Ubuntu 16.04 by running:
 ```
 vagrant ssh
@@ -49,6 +50,8 @@ exit
 vagrant reload
 ```
 
+You can then choose to upgrade to either PHP 7.1 or PHP 7.2.
+
 > **Note:** the initial download of the (~2GB) box image could take some time
 > so please be patient.