checkTheAbilityToStartADriverWithTheDefaultServerAndNotDefaultNode run time error

gistfile1.txt

org.openqa.selenium.WebDriverException: An unknown server-side error occurred while processing the command. Original error: Could not find adb Please set the ANDROID_HOME environment variable with the Android SDK root directory path. (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 1.72 seconds
Build info: version: '2.53.0', revision: '35ae25b1534ae328c771e0856c93e187490ca824', time: '2016-03-15 10:43:46'
System info: host: 'Vikrams-MacBook-Pro.fritz.box', ip: '192.168.178.33', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.11.5', java.version: '1.8.0_45'
Driver info: io.appium.java_client.android.AndroidDriver
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
	at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:206)
	at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:158)
	at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:678)
	at io.appium.java_client.DefaultGenericMobileDriver.execute(DefaultGenericMobileDriver.java:51)
	at io.appium.java_client.AppiumDriver.execute(AppiumDriver.java:1)
	at io.appium.java_client.android.AndroidDriver.execute(AndroidDriver.java:1)
	at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:249)
	at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:131)
	at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:144)
	at io.appium.java_client.DefaultGenericMobileDriver.<init>(DefaultGenericMobileDriver.java:47)
	at io.appium.java_client.AppiumDriver.<init>(AppiumDriver.java:114)
	at io.appium.java_client.AppiumDriver.<init>(AppiumDriver.java:145)
	at io.appium.java_client.AppiumDriver.<init>(AppiumDriver.java:174)
	at io.appium.java_client.android.AndroidDriver.<init>(AndroidDriver.java:184)
	at com.saucelabs.appium.driver_service.DriverServiceSample.checkTheAbilityToStartADriverWithTheDefaultServerAndNotDefaultNode(DriverServiceSample.java:79)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)