Update ruby version and change crontab job

.ruby-version

@@ -1 +1 @@
-ruby-1.9.3-p484
+ruby-2.4.3

etc/daily_mailer

@@ -1,7 +1,12 @@
+#
+# Not used. We now call docker from crontab
+#  /usr/bin/docker run --network smartmeter_default --rm smartmeter_smartmeter ruby report_mailer.rb
+#
+
 #!/usr/bin/env bash
 
 # load rvm ruby
-source /usr/local/rvm/environments/ruby-1.9.3-p484@smartmeter
+source /usr/local/rvm/environments/ruby-2.4.1@smartmeter
 
 cd /home/pcog/smartmeter
 ruby report_mailer.rb