Added PyYAML in requirements
Moved sample of configuration in devstack dir
Inial simple implementation of migration script
Trivial logic of migration

A source server suspended until a destination server was created.
Removed unused block of code
Changed default level of logging to INFO
Skip flavors according to mapping
Worked version of migration of images
Moved logic of migration servers into a func
Add migrate_tenant() function
Switch logging level to INFO
Extended mapping to images and flavors
Fixed identation error
Additional CLI argument for commands

For example the migration process can be started by command:

    $ python migration.py devstack/config.yaml migrate
Fixed bug with unregistered migration of images
Added a command to cleanup resource

The command removes resources (servers, flavors, images) from a
destination cloud.
Add security group migration

Add function to migrate security groups
Add function to migrate security group rules
Add cleanup of security groups
Add scripts directory and README file for scripts
Add constants for service tenant and default security group

Add SERVICE_TENANT_NAME constant for service tenant, should be
used to preserve service users and tenant
Add RO_SECURITY_GROUPS list to specify read-only security groups,
used for cleanup purposes
Move migration.py script to scripts/ directory