Added contrail::system_config, added unit tests

contrail::system_config configure the basic system parameters to
make the system ready to run contrail control node applications in it.

Also enabled rspec, added unit tests for contrail::system_config
Merge pull request #3 from hkumarmk/system_config

Added contrail::system_config, added unit tests
Added rabbitmq management code

Added rabbitmq management code, added a parameter to specify
  whether rabbitmq to be managed within this module or not.
Added zookeeper management code

zookeeper management code has been added.
Two parameters added to class contrail,
  1. manage_zookeepr: Whether to manage zookeeper in this module
  2. zookeeper_server_id: A unique id within the zookeeper cluster.
Added haproxy management

Added optional haproxy management code, also added two parameters
to contrail class,

1. manage_haproxy - Whether to manage haproxy in this module
2. control_ip_list - An array of contrail control node IP list
Added cassandra management code

Added cassandra management code to contrail module
Added redis management code

Added optional redis management code to contrail
Added contrail ifmap-server management code

Added contrail ifmap-server management code with unit tests.