PHP 7.1: improve Code Quality section of README.md

README.md

@@ -48,9 +48,11 @@ library redesigning it to depend only on PHP, and no more Javascript.
 
 As stated in [composer.json][6], it requires:
 
-- PHP 5.6+
+- PHP 7.1+
 - PHP DOM extension
 
+To run this library on PHP 5.6+, install its version 1.x.
+
 ## Installation
 
 Use [Composer][7] to download and install this library as well as its dependencies.
@@ -76,27 +78,31 @@ The code of this library:
 - follows the [PSR-4][14] autoloading standard
 - is statically analysed with [PHPQA][15] which wraps several tools, notably [PHPCS][16], [PHPMD][17], [PHPStan][18] and 
 [Psalm][19] 
-- is unit tested with [PHPUnit][20] (code coverage on [Coveralls][21]) and mutation tested with [Infection][22]
-- is continuously integrated on [TravisCI][23]
+- is unit tested with [PHPUnit][20] (code coverage on [Coveralls][21])
+- is mutation tested with [Infection][22]
+- is tested on different versions of PHP (see [.travis.yml][23] for details)
+- has some of its dependencies (those listed by the [PHP Security Advisories Database][24]) checked for known security 
+issues
+- is continuously integrated on [TravisCI][25]
 
 These tools are installed with the library as long as you do not specify the option `--no-dev` when running the 
 `install` or `update` [Composer][7] commands.
 
-To run the static analysis tools and the unit tests:
+To run the static analysis tools and the unit tests via [PHPQA][15]:
 
 ```bash
 ./vendor/bin/phpqa --analyzedDirs=. --ignoredDirs=build,tests,vendor --report
 ```
 
-To see the reports generated by these tools use a browser to open the file `./build/phpqa.html`. 
+To see the reports generated by [PHPQA][15] use a browser to open the file `./build/phpqa.html`. 
 
 ## Author
 
-[Benoit Borrel][24]
+[Benoit Borrel][26]
 
 ## License
 
-This library is licensed under the GPL-3.0-only License, see the [LICENSE.md][25] file for details.
+This library is licensed under the GPL-3.0-only License, see the [LICENSE.md][27] file for details.
 
 [1]: https://en.wikipedia.org/wiki/Google_Scholar
 [2]: https://scholar.google.com/
@@ -120,6 +126,8 @@ This library is licensed under the GPL-3.0-only License, see the [LICENSE.md][25
 [20]: https://phpunit.de/
 [21]: https://coveralls.io/github/bborrel/google-scholar-profile-parser?branch=master
 [22]: https://github.com/infection/infection
-[23]: https://travis-ci.com/bborrel/google-scholar-profile-parser
-[24]: https://github.com/bborrel
-[25]: LICENSE.md
+[23]: .travis.yml
+[24]: https://github.com/FriendsOfPHP/security-advisories
+[25]: https://travis-ci.com/bborrel/google-scholar-profile-parser
+[26]: https://github.com/bborrel
+[27]: LICENSE.md