Revert "Updated ruby/node images" (#8712)

* Revert "update vagrant configs (#8706)"

This reverts commit 8971bb8c.

* Revert "Updated ruby/node images (#8700)"

This reverts commit 5aae71cf.

Dockerfile

-FROM node:8.12.0-alpine as node
-FROM ruby:2.5.1-alpine3.7
+FROM node:8.11.3-alpine as node
+FROM ruby:2.4.4-alpine3.6
 
 LABEL maintainer="https://github.com/tootsuite/mastodon" \
       description="Your self-hosted, globally interconnected microblogging community"