Fix to 403 error. Added headers

[barrypearseburke]

Fixed the issue by adding HEADERS = {'User-Agent': 'Mozilla/5.0'}

[barrypearseburke]

from eircode.address import Address
address = Address('4 MAIN STREET, Co. CLARE', proxy=False, reverse=False)
address
<eircode.address.Address object at 0x0000020259E1D400>
address.serialize()
{'display_name': '4 MAIN STREET, TULLA, Co. CLARE', 'link': None, 'eircode': {'routing_key': 'V95', 'unique_identifier': 'F3C9', 'eircode': 'V95F3C9', 'county': 'Clare', 'towns': ['Miltown Malbay', 'Ennis', 'Kildysart']}}
address = Address('4 MAIN STREET, Co. CLARE', proxy=True, reverse=False)
Deleting gateways for site 'https://api-finder.eircode.ie'.
Deleted 10 endpoints with for site 'https://api-finder.eircode.ie'.
Starting API gateways in 10 regions.
Using 10 endpoints with name 'https://api-finder.eircode.ie - IP Rotate API' (10 new).
address
<eircode.address.Address object at 0x000002025A203F10>
address.serialize()
{'display_name': '4 MAIN STREET, TULLA, Co. CLARE', 'link': None, 'eircode': {'routing_key': 'V95', 'unique_identifier': 'F3C9', 'eircode': 'V95F3C9', 'county': 'Clare', 'towns': ['Miltown Malbay', 'Ennis', 'Kildysart']}}