Fix a typo
Increase wait times for window_opened_by spec due to slow Travis CI
Test should be tagged as :windows also
Update History.md

Fix typo
Use Rack::Lock to prevent concurrency when eager_load is false
Update visit's documentation to indicate that it requires something that can become a string
Always convert visit's URL to a String before manipulation

It is convenient to be able to pass in URI objects to `visit`, but
these need to be coerced to a string before actual usage. Most of
visit's code paths would convert the incoming url to a string
as-needed. However, the path used when `always_include_port` is
enabled did not, causing an error where `URI.parse` would try to parse
an existing URI object.

This change consolidates the coercion to string at the entrypoint of
the method.
Update fixes in 2.4.2