Add shouldStripHeaderOnRedirect to Request

[dzhus]

As discussed in #300 (comment)

We don't change the current behaviour hence no major bump

[snoyberg]

Looks like the builds are failing:

    /Users/travis/build/snoyberg/http-client/http-conduit/Network/HTTP/Simple.hs:356:25: error:
        • Variable not in scope: (<>) :: H.Query -> H.Query -> t
        • Perhaps you meant one of these:
            ‘<$>’ (imported from Prelude), ‘*>’ (imported from Prelude),
            ‘<$’ (imported from Prelude)
        |
    356 |     where q = additions <> getRequestQueryString req

[dzhus]

It's unrelated – master is broken too (see #387, then I'll rebase)

[dzhus]

@snoyberg All green now

[snoyberg]

LGTM, thanks! And thank you doubly for fixing CI!