Move docstring to FakeMachineBase
Move docstring to FakeMachineBase

This change moves FakeMachine docstring to FakeMachineBase because it is
valid for all FakeMachineBase subclasses.

Change-Id: Ic30098f7d84dd3a5d6c5f7ff675d3f6e7b0a4cae

openstack/neutron,MaximNevrov/neutron,shahbazn/neutron,mattt416/neutron,bigswitch/neutron,dims/neutron,takeshineshiro/neutron,yanheven/neutron,sasukeh/neutron,wolverineav/neutron,neoareslinux/neutron,huntxu/neutron,klmitch/neutron,mahak/neutron,yanheven/neutron,mahak/neutron,adelina-t/neutron,neoareslinux/neutron,skyddv/neutron,openstack/neutron,javaos74/neutron,skyddv/neutron,cloudbase/neutron,javaos74/neutron,mmnelemane/neutron,igor-toga/local-snat,jumpojoy/neutron,silenci/neutron,mahak/neutron,chitr/neutron,klmitch/neutron,barnsnake351/neutron,takeshineshiro/neutron,shahbazn/neutron,vivekanand1101/neutron,sebrandon1/neutron,barnsnake351/neutron,asgard-lab/neutron,dims/neutron,JianyuWang/neutron,glove747/liberty-neutron,dhanunjaya/neutron,swdream/neutron,eayunstack/neutron,eayunstack/neutron,chitr/neutron,bigswitch/neutron,sebrandon1/neutron,adelina-t/neutron,SamYaple/neutron,apporc/neutron,swdream/neutron,cloudbase/neutron,noironetworks/neutron,apporc/neutron,JianyuWang/neutron,igor-toga/local-snat,wolverineav/neutron,noironetworks/neutron,MaximNevrov/neutron,mattt416/neutron,jumpojoy/neutron,vivekanand1101/neutron,sasukeh/neutron,SamYaple/neutron,dhanunjaya/neutron,asgard-lab/neutron,glove747/liberty-neutron,huntxu/neutron,silenci/neutron,openstack/neutron,mmnelemane/neutron