Add scrutinizer badges to README.

Also removes the unstable build badge, which is kind of redundant since
we will always respect the pattern of keeping the `master` branch stable
enough to be used.

Two Scrutinizer badges were added: code coverage and code quality.

Travis changed to report code coverage to Scrutinizer.
Removes new line from beggining of file.

Since this is considered output by PHP and could harm the output buffer
for requests that will send headers after this.

Nasty bug.
Merge pull request #193 from augustohp/189-scrutinizer

Scrutinizer code coverage and custom Makefile support
Cleaning up the code and making it PSR1/2 compatible

More cleaning
Merge pull request #192 from gabrielsch/patch-1

Cleaning up RecursiveTreeIterator class
Added branch alias
PSR-4 autoloading
Merge pull request #182 from GrahamCampbell/psr-4

PSR-4 support instead of PSR-0.
Merge pull request #194 from GrahamCampbell/alias

Branch alias added on composer.

Alias the `master` branch to the next milestone (tag).
Fixing tests/bootstrap.php for #182
Links of rules on README.

All references to rules inside the README now have
a link to the corresponding section into the documentation.

Related to #190 on GitHub.