Added ex_create_balancer_policy() and ex_destroy_balancer_policy() method

Added test suite for ex_create_balancer_policy() and ex_destroy_balancer_policy() method

Added ex_set_balancer_policies_listener(self, balancer) method

added all the methods required for adding & deleting policies

corrected the docstring and positioning of methods

added testsuits for extension methods

fixture for ex_create_balancer_policy() method

fixture for ex_list_balancer_policies() method

fixture for ex_list_balancer_policy_types() method

fixture for ex_set_balancer_policies_backend_server() method

fixture for ex_set_balancer_policies_listener() method

removed basestring for python 3 support

PEP8 guidelines fixture

added the documentation for the extension methods

corrected various docstrings

corrected various docstrings and lint

correct the lint and added argument names

pep8 fixtures

pep8 fixtures

made changes in the doc

python code of creating connection for the doc

made changes in the doc

python code for creating policy for doc ref

python code for creating load balancer for doc ref

python code for creating balancer listeners for doc ref

python code for deleting balancer policy for doc ref

python code for listing  balancer policies for doc ref

python code for listing  balancer policy types for doc ref

python code for set balancer policy types for backend server

python code for set balancer policy types for listeners

list all the load balancers

all method implemetation of ELB driver

improved the documentation

pep8 correction

removed indendation error

update the docstrings

update the docstrings

removed invalid syntax

removed sphinx build errors