[PATCH][jmh-jdk-microbenchmarks] Update pom to use JMH 1.21

[Jonathan Gibbons]

OK.

-- Jon


On 5/7/18 10:40 AM, Eric Caspole wrote:
> Hi everyone,
> Could I have a review and a sponsor for this new webrev that updates 
> the pom for jmh-jdk-microbenchmarks to use the new JMH v1.21, which 
> has fixes that are immediately useful to us.
>
> http://cr.openjdk.java.net/~ecaspole/use_1.21/webrev/
>
> Thanks,
> Eric