[PRD-999] move hosts_file class call in os_common
Merge pull request #582 from Mirantis/prd999

[PRD-999] move hosts_file class call in os_common
Fix hosts file creation class
Merge pull request #583 from monroid/fix_hosts

Fix hosts file creation class
[PRD-1871] fix race condition for nailyfacts
Merge pull request #586 from Mirantis/prd1871

[PRD-1871] fix race condition for nailyfacts
enable apache mod_proxy for ubuntu
Merge pull request #588 from Zipfer/apache_api_proxy

enable apache mod_proxy for ubuntu
fixed syntax error in pmanager.py
Merge pull request #591 from kozhukalov/prd1872

fixed syntax error in pmanager.py
Savanna refactoring
Merge pull request #592 from dmitryilyin/savanna_only

Savanna only without murano/heat merge request