RFR: Fix maven-surefire-plugin version

[Aleksey Shipilev]

Maven complains otherwise:

[WARNING]
[WARNING] Some problems were encountered while building the effective model for
org.openjdk.jol:jol-core:jar:0.14-SNAPSHOT [WARNING] 'build.plugins.plugin.version' for
org.apache.maven.plugins:maven-surefire-plugin is missing. @ org.openjdk.jol:jol-core:[unknown-version],
/home/shade/temp/jol/jol/jol-core/pom.xml, line 66, column 21 [WARNING]  [WARNING] It is highly recommended to fix
these problems because they threaten the stability of your build. [WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.

-------------

Commit messages:
 - Fix maven-surefire-plugin version

Changes: https://git.openjdk.java.net/jol/pull/6/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jol&pr=6&range=00
  Stats: 5 lines in 1 file changed: 5 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jol/pull/6.diff
  Fetch: git fetch https://git.openjdk.java.net/jol pull/6/head:pull/6

PR: https://git.openjdk.java.net/jol/pull/6