Bump HikariCP from 3.4.5 to 4.0.3 in /modules/spock

Bumps [HikariCP](https://github.com/brettwooldridge/HikariCP) from 3.4.5 to 4.0.3.
- [Release notes](https://github.com/brettwooldridge/HikariCP/releases)
- [Changelog](https://github.com/brettwooldridge/HikariCP/blob/dev/CHANGES)
- [Commits](brettwooldridge/HikariCP@HikariCP-3.4.5...HikariCP-4.0.3)

Signed-off-by: dependabot[bot] <support@github.com>

modules/spock/build.gradle

@@ -12,7 +12,7 @@ dependencies {
     testCompile project(':mysql')
     testCompile project(':postgresql')
 
-    testCompile 'com.zaxxer:HikariCP:3.4.5'
+    testCompile 'com.zaxxer:HikariCP:4.0.3'
     testCompile 'org.apache.httpcomponents:httpclient:4.5.13'
 
     testRuntime 'org.postgresql:postgresql:42.2.18'