[ticket/11145] Wrong error thrown when uploading a bigger image.

When attaching an image to a post with a size larger than maximum defined in
php.ini, 'ATTACHED_IMAGE_NOT_IMAGE' error is thrown. $file->is_image() is
returning false value when image size is too large. Therefore, moved
not image test down after image size test.

PHPBB3-11145
[ticket/11568] Use Goutte Client to install the board for functional tests

PHPBB3-11568
[ticket/11568] Set client manually so we can increase the cURL timeout

PHPBB3-11568
[ticket/11568] Any output before the doc type means there was an error

Change is needed to allow "Warning:" in the HTML body

PHPBB3-11568
[ticket/11568] Only use a static version of the client

PHPBB3-11568
[ticket/11568] Remove manual calls to assert_response_success()

PHPBB3-11568
[ticket/11568] Make CookieJar static aswell

PHPBB3-11568
[ticket/11568] Fix common_groups_test.php form handling

PHPBB3-11568
[ticket/11580] Enable --no-interaction option on composer for travis

There is no interaction available on travis ;)

PHPBB3-11580
[ticket/11580] Enable prefer-source option (should error way less)

PHPBB3-11580
Merge remote-tracking branch 'nickvergessen/ticket/11580' into develop-olympus

* nickvergessen/ticket/11580:
  [ticket/11580] Enable prefer-source option (should error way less)
  [ticket/11580] Enable --no-interaction option on composer for travis
[ticket/11568] Trim the output to allow Tabs before INCLUDE overall_header

PHPBB3-11568
[ticket/11568] Allow different status codes

PHPBB3-11568
[ticket/11568] Add method to get page content

PHPBB3-11568
[ticket/11568] Only assert string when doctype is there at all

PHPBB3-11568
[ticket/11568] Remove unused method

PHPBB3-11568
[ticket/11568] Use static calls for static methods

PHPBB3-11568
[ticket/11568] Invert logic for asserting the response

PHPBB3-11568
[ticket/11568] Add comma at end of array key-value couple

PHPBB3-11568
[ticket/11568] Split status code and html debug assertion into two methods

PHPBB3-11568