📍 Pin version of thin

Thin 2.0 was released June 22 (ish), so... We need to pin Thin to 1.X.

This is embarrassing in a way, but also a great debugging opportunity every couple of years! 😬😅

dockercoins/hasher/Dockerfile

@@ -1,7 +1,7 @@
 FROM ruby:alpine
 RUN apk add --update build-base curl
 RUN gem install sinatra --version '~> 3'
-RUN gem install thin
+RUN gem install thin --version '~> 1'
 ADD hasher.rb /
 CMD ["ruby", "hasher.rb"]
 EXPOSE 80