(TK-33) Add proxy redirect test

Add a proxy redirect test to the proxy test file.
(TK-33) Add redirect support to proxy

Add redirect support to the proxy by setting the HTTPClient
created by Jetty to follow redirects. Add tests for this
functionality.
(TK-33) Add `:follow-redirects` proxy option

Add a `:follow-redirects` proxy option, which allows the user to
specify whether the HttpClient created by a ProxyServlet follows
redirects.
(TK-33) Explicitly set default follow redirects

Explicitly set the followRedirects setting on the HttpClient
created by a ProxyServlet in the default case. Cleanup redirect
tests.
(TK-33) Remove unused macro

Remove unused `with-target-and-proxy-servers-redirect` macro.
(TK-33) Update non-proxied path test

Update non-proxied path test to verify that the ProxyServlet
can follow a redirect from the target server to a location
not under the original proxy path.
Merge pull request #59 from fpringvaldsen/TK-33-proxy-redirect

(TK-33) Add redirect support to proxying