Updated the way jtalks-cicd is installed - first we pip-install the mysql-connector-python because it does not get installed via setuptools by jtalks-cicd package (the mysql package is now hosted on a different host and therefore pip does not trust to it and the installation fails). This is a dirty hack, but our hands are tied here.

Also, added plugins auto-installation according to a workaround listed [on GitHub](https://github.com/mitchellh/vagrant/issues/1874). As for now Vagrant does not support plugin auto-installation out-of-box.