Added usage example for sbt and maven in README.md.

Author: cheeseng

README.md

@@ -1,6 +1,27 @@
 # ScalaTest + Selenium
 ScalaTest + Selenium provides integration support between ScalaTest and Selenium.
 
+**Usage**
+
+To use it for ScalaTest 3.1.0 and Selenium 2.45.x: 
+
+SBT: 
+
+```
+libraryDependencies += "org.scalatestplus" %% "selenium-2-45" % "3.1.0.0" % "test"
+```
+
+Maven: 
+
+```
+<dependency>
+  <groupId>org.scalatestplus</groupId>
+  <artifactId>selenium-2-45</artifactId>
+  <version>3.1.0.0</version>
+  <scope>test</scope>
+</dependency>
+```
+
 **Publishing**
 
 Please use the following commands to publish to Sonatype: