Use spring-boot-starter-data-mongodb-reactive
Use spring-boot-starter-data-mongodb-reactive

This commit also cleanup Gradle build.

sdeleuze/mixit,mixitconf/mixit,mix-it/mixit,mix-it/mixit,sdeleuze/mixit,mixitconf/mixit,mix-it/mixit,mixitconf/mixit,sdeleuze/mixit,mix-it/mixit,mix-it/mixit,mixitconf/mixit,sdeleuze/mixit