Used `commons-lang3` does not support java 11

[b4eEX]

Trying to use graphql-java-tools on JDK 11 results in exceptions like:

11:50:18.763 [main] DEBUG graphql.execution.ExecutionStrategy - '60a7e98f-9aa4-4cca-95c9-f5a9481e36fb', field '/fieldName' fetch threw exception
java.lang.NullPointerException: null
	at org.apache.commons.lang3.SystemUtils.isJavaVersionAtLeast(SystemUtils.java:1654)

Root problem appears to be commons-lang3:3.7, which somehow fails on newer JVMs, with latest version, 3.8.1, working OK.

Hopefully, I'll submit a PR to fix it soon.