Rename HTTP.with_follow to HTTP.follow

- Follow options now have default value
- HTTP.with_follow marked as deprecated

New signature allows writing better looking code:

  # with default options
  HTTP.follow.get "http://example.com/"

  # with custom options
  HTTP.follow(:max_hops => 10).get "http://example.com/"
update example to work with latest syntax
Merge pull request #131 from seamusabshere/patch-2

update example to work with latest syntax
Fix typo and update an example
Merge pull request #132 from havenwood/patch-1

Fix typo and update an example
Extract response status and provide some sugar.

Example:

    res = HTTP.get "http://example.com"
    fail "something wrong" unless res.status.ok?