Codeception issue #1510 - site-root relative URL handling

Changing Guzzle::getAbsoluteUri to handle site-root relative URLs.  This
changes how PhpBrowser handles relative URLs everywhere, including
amOnPage, click(), submitForm, etc...
Update composer.json
Updating WebDriver amOnPage to handle relative URLs

WebDriver was handling site-root relative URLs in the same way as
doc-relative.  This has been updated so a site-relative URL is relative
to the domain specified in the 'url' configuration setting.
Update composer.json
Cleaner code to match relative URLs

Building the URL with PHP's parse_url then passing it to
\GuzzleHttp\Url::buildUrl
Secondary code cleanup

Sorry - silly first commit had lines that could be further cleaned on
second thought.
Fixed missing bracket
Updated TestsForWeb test to use existing page

FrameworksTest fails with a non-existent URL - updated the last amOnPage
in testSiteRootRelativePathsForBasePathWithSubdir to use a real page.
Merge pull request #1537 from eddiejaoude/patch-1

Fixed missing bracket
Merge pull request #1530 from urakozz/2.0

[composer] Allow Guzzle 5 (it looks compatible with 4.*)
version bump
updated composer lock
changed error exception. Fix #1503
updated changelog
added test for error descriptions. Issue #1503
Complex checkboxes fixed. Fix #1535
added c3_url parameter. Fix #1024
fixed Soap test
increase delay for selenium
changelog updated