Add other tests to boost the coverage of Conn.Plug
Merge pull request #129 from whatyouhide/plug-conn-coverage

Plug conn coverage
Merge pull request #130 from whatyouhide/master

SVG Travis badge ftw
Handle struct values when stringifying params
Check struct is an atom for proper type check
Merge pull request #131 from chrismccord/master

Handle struct values when stringifying params
Ensure custom call is always invoked before handle errors
Remove secure:true from Plug.Session ETS example in docs
Fail in Plug.Conn.put_status/2 when the resp had already been sent

Most of the `Plug.Conn` functions raise an `AlreadySentError` when the
response has already been sent. This commit introduces the code and tests that
make this function behave like the others.
Merge pull request #133 from whatyouhide/checks-on-put-status

Fail in Plug.Conn.put_status/2 when the resp had already been sent
docs(README.md): fix typos
Merge pull request #135 from Gazler/docs/readme-typos

docs(README.md): fix typos
Merge pull request #132 from HashNuke/remove-secure-from-ets-example

Remove secure:true from Plug.Session ETS example in docs
Crsf protection test
Initial CSRF protection
Move the Plug.Router.build_host/1 method to Plug.Router.Utils

I move the above-mentioned method to `Plug.Router.Utils` and renamed it to the
more accurate `build_host_match/1`; I also added some doctests.

I also "incidentally" added some explanatory comments to the
`Plug.Router.forward/2` macro.
Merge pull request #138 from whatyouhide/tiny-cleanups

Move the Plug.Router.build_host_match/1 method to Plug.Router.Utils
Fix exception message typo
Merge pull request #140 from twined/master

Fix exception message typo
Add support for case-insensitivity in MethodOverride

Now the `Plug.MethodOverride` plug supports case-insensitive methods both in the
`_method` parameter and in the `X-HTTP-Method-Override` header. I also updated
the docs for this plug.