Backport unpinning of de.flapdoodle.embed.mongo version

Closes gh-3339

Author: shakuzen

dependencies.gradle

@@ -27,7 +27,7 @@ def VERSIONS = [
         'com.wavefront:wavefront-sdk-java:latest.release',
         // 3.1.3 falis on Mac OS, 3.0.0 is the last release before that version
         // https://github.com/flapdoodle-oss/de.flapdoodle.embed.mongo/issues/352
-        'de.flapdoodle.embed:de.flapdoodle.embed.mongo:3.0.0',
+        'de.flapdoodle.embed:de.flapdoodle.embed.mongo:3.+',
         'io.dropwizard.metrics:metrics-core:4.0.+',
         'io.dropwizard.metrics:metrics-graphite:4.1.+',
         'io.dropwizard.metrics:metrics-jmx:4.0.+',