Removing specific nhs signature

@jakul Removing specific nhs signature.


Output:
```
(Pdb) message.fragments
[<email_reply_parser.Fragment object at 0x15cec10>, <email_reply_parser.Fragment object at 0x15cec90>, <email_reply_parser.Fragment object at 0x15cebd0>]
(Pdb) message.fragments[0].content
'Zsofia Meszaros\nAssistant Practice Manager\n'
(Pdb) message.fragments[1].content
'Lilyville Surgery, 630 Fulham Road, London SW6 5RS\n\nTel 020 7731 5130, 020 7731 9388(direct line)\n'
(Pdb) message.fragments[2].content
'Fax 020 7736 4985'
```

All test ran OK

```
(hurdle)administrator@vagrant-khan:/src/email-reply-parser$ python setup.py test
running test
running egg_info
writing email_reply_parser.egg-info/PKG-INFO
writing top-level names to email_reply_parser.egg-info/top_level.txt
writing dependency_links to email_reply_parser.egg-info/dependency_links.txt
reading manifest file 'email_reply_parser.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
warning: no files found matching 'VERSION'
writing manifest file 'email_reply_parser.egg-info/SOURCES.txt'
running build_ext
test_captures_date_string (test.test_email_reply_parser.EmailMessageTest) ... ok
test_complex_body_with_one_fragment (test.test_email_reply_parser.EmailMessageTest) ... ok
test_deals_with_windows_line_endings (test.test_email_reply_parser.EmailMessageTest) ... ok
test_email_one_is_not_on (test.test_email_reply_parser.EmailMessageTest) ... ok
test_multiline_reply_headers (test.test_email_reply_parser.EmailMessageTest) ... ok
test_reads_bottom_message (test.test_email_reply_parser.EmailMessageTest) ... ok
test_reads_top_post (test.test_email_reply_parser.EmailMessageTest) ... ok
test_reply_is_parsed (test.test_email_reply_parser.EmailMessageTest) ... ok
test_sent_from_iphone (test.test_email_reply_parser.EmailMessageTest) ... ok
test_simple_body (test.test_email_reply_parser.EmailMessageTest) ... ok
test_verify_reads_signature_correct (test.test_email_reply_parser.EmailMessageTest) ... ok
test_Regards (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_best_regards (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_confidential (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_email_disclaimer (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_intended_recipients_only (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_kind_regards (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_many_thanks (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_nhs_net_quoting (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_nhs_net_quoting2 (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_nhs_net_quoting3 (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_nhs_net_quoting4 (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_nhs_remove_signature (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_regards (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_regards_signature (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_sent_from_samsung_mobile (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_stars (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok
test_underscores (test.test_email_reply_parser.NHSNETEmailMessageTest) ... ok

----------------------------------------------------------------------
Ran 28 tests in 0.078s

OK
```