Bump postgresql from 42.2.10 to 42.2.12 in /modules/postgresql

Bumps [postgresql](https://github.com/pgjdbc/pgjdbc) from 42.2.10 to 42.2.12.
- [Release notes](https://github.com/pgjdbc/pgjdbc/releases)
- [Changelog](https://github.com/pgjdbc/pgjdbc/blob/master/CHANGELOG.md)
- [Commits](pgjdbc/pgjdbc@REL42.2.10...REL42.2.12)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

modules/postgresql/build.gradle

@@ -3,7 +3,7 @@ description = "Testcontainers :: JDBC :: PostgreSQL"
 dependencies {
     compile project(':jdbc')
 
-    testCompile 'org.postgresql:postgresql:42.2.10'
+    testCompile 'org.postgresql:postgresql:42.2.12'
     testCompile 'commons-dbutils:commons-dbutils:1.7'
     testCompile 'com.zaxxer:HikariCP-java6:2.3.13'
 }