IssueInstant should be UTC

Using SimpleDateFormat converts a date to local time, you need to setTimeZone on the formatter to fix this.

Author: jrowny

src/main/java/com/onelogin/saml/AuthRequest.java

@@ -9,6 +9,7 @@
 import java.net.URLEncoder;
 import java.text.SimpleDateFormat;
 import java.util.Date;
+import java.util.TimeZone;
 import java.util.Map;
 import java.util.UUID;
 import java.util.zip.Deflater;
@@ -34,6 +35,7 @@ public AuthRequest(AppSettings appSettings, AccountSettings accSettings){
 		this.accountSettings = accSettings;
 		id="_"+UUID.randomUUID().toString();
 		SimpleDateFormat simpleDf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
+		simpleDf.setTimeZone(TimeZone.getTimeZone("UTC"));
 		issueInstant = simpleDf.format(new Date());
 	}