Print out tweets for the last five events after a successful run

.travis.yml

@@ -1,2 +1,4 @@
 language: node_js
 cache: yarn
+
+after_success: ./scripts/print_welcome_tweet.sh

scripts/print_welcome_tweet.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+DIRECTORY="_data/events_gdcr2018"
+FILES=$(ls $DIRECTORY/*.json)
+
+LAST_5_EVENTS=$(for i in $FILES; do git --no-pager log --diff-filter=A --follow --format="%at $i" -- $i | tail -1; done | sort | tail -n 5 | awk '{ print $2 }')
+
+echo "Here are tweetable welcome messages for the latest five events registered (as per git)"
+echo ""
+
+for j in $LAST_5_EVENTS;
+  do
+    jq -r '"Welcome \"" + .title + "\" with " + (.moderators | join(", ")) + " in " + .location.city + ", " + .location.country + " to #gdcr18! See the link for more information " + .url' $j;
+  done