my-stamps.ru: move to another hosting

[php-coder]

Similar to #71 but we also should try to automate most of the things (see also #267). During this transition we also switch to a newer version of Ubuntu 16.04. LTS, Java and MySQL.

Subtasks:

• Ansible: configure vagrant+ansible #268 add Vagrantfile and setup Ansible
• Ansible: install JDK #269 install JDK
• Ansible: run mystamps with test profile #270 run mystamps site with H2
• Ansible: install nginx #271 install nginx
• Configure mysql (manually)
• Use prod profile
• Configure cron task for doing backups
• vagrant: task php-coder.nginx : Run and enable Nginx to start on boot fails after removing default configuration files
• Configure ssh (manually)
• Import MySQL backup (manually)
• Install and configure apticron (manually)
• Configure exim (manually)
• Configure my-stamps.ru domain's settings to point to an instance
• Configure MailGun to work with a new instance (manually configure domain's settings)
• Create PTR record (DO already provides that for us)
• Use systemd script
• Activate swap file (manually) (also added vm.swappiness = 30)
• Fix deploy to the prod (Failed to stop mystamps.service: Interactive authentication required)

[php-coder]

For the record: I decided to not install newrelic (for Java and server monitoring), logentries and fail2ban because we have too small memory on the new server.