A few fixes to the readme.md for Spring-Boot branch

Merge pull request #169 from aaguilera/springboot

readme.md

-# Sprinb Boot version of the Spring PetClinic Sample Application [![Build Status](https://travis-ci.org/spring-projects/spring-petclinic.png?branch=master)](https://travis-ci.org/spring-projects/spring-petclinic/)
+# Spring Boot version of the Spring PetClinic Sample Application [![Build Status](https://travis-ci.org/spring-projects/spring-petclinic.png?branch=master)](https://travis-ci.org/spring-projects/spring-petclinic/)
 
 ## Understanding the Spring Petclinic application with a few diagrams
 <a href="https://speakerdeck.com/michaelisvy/spring-petclinic-sample-application">See the presentation here</a>
@@ -7,6 +7,7 @@
 ```
 	git clone https://github.com/spring-projects/spring-petclinic.git
 	cd spring-petclinic
+	git checkout springboot
 	./mvnw spring-boot:run
 ```