[Java] Upgrade to Checkstyle 8.17.

Author: mjpt777

build.gradle

@@ -124,7 +124,7 @@ subprojects {
     jar.enabled = true
 
     dependencies {
-        checkstyle 'com.puppycrawl.tools:checkstyle:8.16'
+        checkstyle 'com.puppycrawl.tools:checkstyle:8.17'
 
         compile 'org.agrona:agrona:0.9.30'
 
@@ -134,7 +134,7 @@ subprojects {
     }
 
     checkstyle {
-        toolVersion = '8.16'
+        toolVersion = '8.17'
     }
 
     compileJava {
@@ -160,7 +160,7 @@ subprojects {
 
     javadoc {
         title = '<h1>Simple Binary Encoding</h1>'
-        options.bottom = '<i>Copyright &#169; 2014-2018 Real Logic Ltd. All Rights Reserved.</i>'
+        options.bottom = '<i>Copyright &#169; 2014-2019 Real Logic Ltd. All Rights Reserved.</i>'
         if (JavaVersion.current().ordinal() >= JavaVersion.VERSION_1_10.ordinal()) {
             options.addBooleanOption 'html5', true
         }