Upgrade to Selenium 3.1.0

Closes gh-8381

spring-boot-dependencies/pom.xml

@@ -144,7 +144,7 @@
 		<rxjava.version>1.2.6</rxjava.version>
 		<rxjava-adapter.version>1.2.1</rxjava-adapter.version>
 		<rxjava2.version>2.0.6</rxjava2.version>
-		<selenium.version>2.53.1</selenium.version>
+		<selenium.version>3.1.0</selenium.version>
 		<selenium-htmlunit.version>2.21</selenium-htmlunit.version>
 		<sendgrid.version>2.2.2</sendgrid.version>
 		<servlet-api.version>3.1.0</servlet-api.version>