Add Lookup::Test.reset to README 

The method `#reset` for clearing stubs
was previously unmentioned in the README

Added LocationIQ provider

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/

Make geocoded? return false with single coordinate

support canada for geocodio

Use sqlite ruby math extensions if present

Add test coverage for LocationIQ lookup

Fix result of ipinfo.io for loopback address (127.0.0.1)

Prevent rake task crash when BATCH not specified

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.

Use sqlite_ext 1.5.0 which has been broadened to work with Ruby
versions prior to 2.x, and remember to add it to files in the
./gemfiles/ directory for use with CI tests, not just to
Gemfile in the root directory.

Fix ambiguous 1st argument warnings in Ruby 2.3.x

Add .ruby-version to .gitignore

Was causing:

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

* handles unreachable network exception

* adds network error class

* tests unreachable host exception handling

Change SmartyStreets Zipcode API.

Smarty street's new zipcode api endpoint as of 26 March 2016.
http://status.smartystreets.com/incidents/4hjpfqh9q2k7

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.