Value didn't match docs at https://smartystreets.com/docs/cloud/us-street-api

In the sea for example
[Fix #1131]

to_kilometers
to_miles
to_nautical_miles
mi_in_km
km_in_mi
km_in_nm
nm_in_km

add new lookup to lookup.rb

add new lookup file ban_data_gouv_fr.rb

add new results file ban_data_gouv_fr.rb

update README with new lookup

create fixtures to test  new lookup

create unit test file for new lookup

update test helper default fixture for new lookup

remove invalid multibyte char (US-ASCII) 'ç' from lookup name

Revert "remove invalid multibyte char (US-ASCII) 'ç' from lookup name"

This reverts commit 7dbfcab4dc4bcb9473edc43651e7d53884f0e24d.

Add '# encoding: utf-8' to files containing special chars

Add '# encoding: utf-8' to files containing special chars

Add '# encoding: utf-8' to files containing special chars

remove useless Geocoder.config from test methods

refacto of ban lookup results method

change city serach param to fit naming conventions in ban lookup test

renamed no results ban lookup fixture to fit tests

removed no search results unnecessary test

remove useless commented code

add alias method to handle state and state_code + move from department to region name as state

refacto results method

support for opencagedata optional parameters

* Refactor calculations

Refactored calculations::extract_coordinates and calculations::coordinates_present?

coordinates_present?
Checks whether an argument matches validating criteria (numeric, not NaN), rather than returning false when matching invalidating criteria.

Also replaced .to_s == NaN with .to_f..nan? 

extract_coordinates 
Now calls coordinates_present? to validate the array, instead of comparing four booleans and initialising extra vars.

* Removed .map and ternary from coordinates_present?

Updated pull request according to Lime's suggestions.

LocationIq # for classes
location_iq # for config

No escaping should be necessary, according to the MaxMind docs:
http://dev.maxmind.com/geoip/geoip2/web-services/

In Rails 5, `rake geocode:all` crashes:

```
$ rake geocode:all CLASS=Whatzit
rake aborted!
ArgumentError: comparison of Fixnum with nil failed
/Users/paul/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0/lib/active_record/relation/batches.rb:217:in `<'
/Users/paul/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0/lib/active_record/relation/batches.rb:217:in `block in in_batches'
/Users/paul/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0/lib/active_record/relation/batches.rb:198:in `loop'
/Users/paul/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0/lib/active_record/relation/batches.rb:198:in `in_batches'
/Users/paul/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0/lib/active_record/relation/batches.rb:120:in `find_in_batches'
/Users/paul/.rvm/gems/ruby-2.2.2/gems/activerecord-5.0.0/lib/active_record/relation/batches.rb:58:in `find_each'
/Users/paul/.rvm/gems/ruby-2.2.2/gems/geocoder-1.2.2/lib/tasks/geocoder.rake:11:in `block (2 levels) in <top (required)>'
/Users/paul/.rvm/gems/ruby-2.2.2/gems/rake-11.2.2/exe/rake:27:in `<top (required)>'
/Users/paul/.rvm/gems/ruby-2.2.2/bin/ruby_executable_hooks:15:in `eval'
/Users/paul/.rvm/gems/ruby-2.2.2/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => geocode:all
(See full trace by running task with --trace)
```

The problem seems to be that `find_each` used to default the `batch:` param when it was explicitly set to nil, but now passes an explicit nil on through.

This patch fixes the issue by defaulting the batch size in the rake task.

Was causing:

    NoMethodError: private method `include' called for
      ActionDispatch::Request:Class

* handles unreachable network exception

* adds network error class

* tests unreachable host exception handling

SmartyStreets is permanently changing their ZIP Code API endpoint by
June 22 at 9am Mountain Time.  The legacy API endpoint is available
until the 22nd.

This change basically changes the API endpoint and updated the tests to
reflect the change.

Intended to fix #1048.