Merge branch 'develop' into staging

* develop:
  update base image

Dockerfile

@@ -1,4 +1,4 @@
-FROM kerstinsieren/alpine-phpfpm-nginx-baseimage:php74-14
+FROM kerstinsieren/alpine-phpfpm-nginx-baseimage:php74-15
 ENV TZ=Europe/Berlin
 COPY . .
 ONBUILD COPY composer.json ./