[#478] Remove Junit 5

We don't really need it at the moment and having
both dependencies on the classpath is a recipe for
errors.

Author: DavideD

hibernate-reactive-core/build.gradle

@@ -26,10 +26,6 @@ dependencies {
     implementation "io.vertx:vertx-sql-client:${vertxVersion}"
 
     // Testing
-    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.0'
-    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
-    testRuntimeOnly 'org.junit.vintage:junit-vintage-engine'
-
     testImplementation 'org.assertj:assertj-core:3.13.2'
     testImplementation "io.vertx:vertx-unit:${vertxVersion}"
 
@@ -94,9 +90,6 @@ tasks.withType(Test) {
 // Example:
 // gradle test -Pdb=MySQL
 test {
-    // Enable JUnit 5
-    useJUnitPlatform()
-
     def selectedDb = project.hasProperty( 'db' )
             ? project.getProperty( 'db' )
             : 'PostgreSQL'