DEV: replace mailcatcher with mailhog (#572)

DEV: replace mailcatcher with mailhog (#572)

diff --git a/image/discourse_dev/Dockerfile b/image/discourse_dev/Dockerfile
index e889974..8967a66 100644
--- a/image/discourse_dev/Dockerfile
+++ b/image/discourse_dev/Dockerfile
@@ -5,10 +5,6 @@ ENV RAILS_ENV development
 
 #LABEL maintainer="Sam Saffron \"https://twitter.com/samsaffron\""
 
-# Install for mailcatcher gem
-RUN apt update && apt install -y libsqlite3-dev \
-    && gem install mailcatcher && rm -rf /var/lib/apt/lists/*
-
 # Remove the code added on base image
 RUN rm -rf /var/www/*
 
@@ -44,3 +40,9 @@ RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo ap
     apt update &&\
     apt install -y google-chrome-stable firefox-esr &&\
     npm install -g eslint babel-eslint
+
+# Install & Configure MailHog (https://github.com/mailhog/MailHog)
+RUN wget -qO /tmp/mailhog https://github.com/mailhog/MailHog/releases/download/v1.0.1/MailHog_linux_amd64\
+    && echo "e2ed634ded49929f089b20045581955ed217672078fd86082dd7a6c67c5d09c7 /tmp/mailhog" | sha256sum -c -\
+    && mv /tmp/mailhog /usr/local/bin/mailhog\
+    && chmod +x /usr/local/bin/mailhog

GitHub sha: ee061f17a9926e41dd4ea13334246939db10ea59

This commit appears in #572 which was approved by SamSaffron. It was merged by techAPJ.