Bump assertj-core from 3.14.0 to 3.15.0 in /modules/junit-jupit… (tes…

…tcontainers#2570)

Bumps [assertj-core](https://github.com/joel-costigliola/assertj-core) from 3.14.0 to 3.15.0.
- [Release notes](https://github.com/joel-costigliola/assertj-core/releases)
- [Commits](assertj/assertj@assertj-core-3.14.0...assertj-core-3.15.0)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>
Co-authored-by: Richard North <rich.north@gmail.com>

modules/junit-jupiter/build.gradle

@@ -12,8 +12,8 @@ dependencies {
     testCompile ('org.mockito:mockito-core:3.3.3') {
         exclude(module: 'hamcrest-core')
     }
+    testCompile 'org.assertj:assertj-core:3.15.0'
     testCompile 'org.junit.jupiter:junit-jupiter-params:5.6.2'
-    testCompile 'org.assertj:assertj-core:3.14.0'
 
     testRuntime 'org.postgresql:postgresql:42.2.12'
     testRuntime 'mysql:mysql-connector-java:8.0.19'