Upgrade Ruby to 2.5.1 (2nd try)

.ruby-version

@@ -1 +1 @@
-2.5.0
+2.5.1

Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:2.5.0
+FROM ruby:2.5.1
 RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs
 RUN mkdir /myapp
 WORKDIR /myapp