Add usage for SBT and Maven in README.md

Author: ikhoon

README.md

@@ -1,6 +1,27 @@
 # ScalaTest + TestNG
 ScalaTest + TestNG provides integration support between ScalaTest and TestNG.
 
+**Usage**
+
+To use it for ScalaTest 3.1.1 and TestNG 6.7: 
+
+SBT: 
+
+```
+libraryDependencies += "org.scalatestplus" %% "testng-6-7" % "3.1.1.0" % "test"
+```
+
+Maven: 
+
+```
+<dependency>
+  <groupId>org.scalatestplus</groupId>
+  <artifactId>testng-6-7</artifactId>
+  <version>3.1.1.0</version>
+  <scope>test</scope>
+</dependency>
+```
+
 **Publishing**
 
 Please use the following commands to publish to Sonatype: