Remove unused dependencies

[Celebrate-future]

@cruftex Hi, I am a user of project org.cache2k.benchmark:util:0.22-SNAPSHOT. I found that its pom file introduced 29 dependencies. However, among them, 7 libraries (24%) have not been used by your project (the redundant dependencies are listed below). This PR helps org.cache2k.benchmark:util:0.22-SNAPSHOT lose weight :) I have tested the revised configuration in my local environment. It is safe to remove the unused libraries.

Best regards

Redundant dependencies----

com.google.code.findbugs:jsr305:jar:3.0.2:compile
com.sun.mail:javax.mail:jar:1.6.0:runtime
com.google.guava:listenablefuture:jar:9999.0-empty-to-avoid-conflict-with-guava:compile
javax.activation:activation:jar:1.1:runtime
com.google.j2objc:j2objc-annotations:jar:1.3:compile
org.codehaus.mojo:animal-sniffer-annotations:jar:1.17:compile
com.google.errorprone:error_prone_annotations:jar:2.3.2:compile