Make error logging more safe

We log failures on cluster startup/scaling in insecure manner. The 'cluster'
variable might be None. For instance, because the cluster was deleted
during the operation. An example could be found in our integration tests here:

jenkins.savanna.mirantis.com/job/gate-savanna-integration/280/consoleText

Search for the string
'NoneType' object has no attribute 'name'

Change-Id: I8fe2be50e7576a54059a8341f9da4d48e87a5968
Update install guide

In development install guide:
* add python-pip package to fedora prerequisites
* add database dev packages
* add step to create database schema

In install guide:
* add step to create database schema

Change-Id: I0b851277b3b295ff76d1b228f7d2be80e1626c5d
Updated from global requirements

Change-Id: If190d10e026ea7c03922c365c9b361a42a01925a
Merge "Update install guide"
Merge "Updated from global requirements"
Merge "Make error logging more safe"