Add Configuration for Proxies

[lukaspanni]

Changes

Added general configuration, currently used to configure proxies for requests.
All methods using requests.HTTP-METHOD now have an additional optional paramter to provide a proxy-config.
If no parameter is provided try to use a optional class-wide proxy-configuration.
If this fails a module-wide Config-Object module_config will be used.
This will make it easy to provide a global config but also to change proxies for every call.
deutschland.Bundesanzeiger uses requests.Session and therefore the proxy configuration is set for the whole session.

Example Code

from deutschland import Geo, Config, module_config

# set proxies in modue-wide config
module_config.set_proxy('http://10.10.1.10:3128', 'https://10.10.1.10:1080')


# class-wide config
local_config = Config({'http': 'http://10.10.1.10:3128', 'https': 'https://10.10.1.10:1080'})
geo = Geo(local_config)    # Overwrite global config and use local_config for all requests
...
# proxies only for the next call
proxies = {'http': 'http://10.10.1.10:3128', 'https': 'https://10.10.1.10:1080'}
data = geo.fetch([52.50876180448243, 13.359631043007212], 
                          [52.530116236589244, 13.426532801586827],
                          proxies)

Addressed Issues

• fixes paranoia mode: requests' proxy support #1