minor #9826 Corrected titles of test tools and use safe url for phpspec (lex111)

This PR was submitted for the 2.7 branch but it was merged into the 2.8 branch instead (closes #9826).

Discussion
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Corrected titles of test tools and use safe url for phpspec

Just another small improvement 😃

Commits
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428120a Corrected titles of test tools and use safe url for phpspec

Author: javiereguiluz

best_practices/tests.rst

@@ -12,7 +12,7 @@ Unit Tests
 Unit tests are used to test your "business logic", which should live in classes
 that are independent of Symfony. For that reason, Symfony doesn't really
 have an opinion on what tools you use for unit testing. However, the most
-popular tools are `PhpUnit`_ and `PhpSpec`_.
+popular tools are `PHPUnit`_ and `PHPSpec`_.
 
 Functional Tests
 ----------------
@@ -112,8 +112,8 @@ Learn More about Functional Tests
 Consider using the `HautelookAliceBundle`_ to generate real-looking data for
 your test fixtures using `Faker`_ and `Alice`_.
 
-.. _`PhpUnit`: https://phpunit.de/
-.. _`PhpSpec`: http://www.phpspec.net/
+.. _`PHPUnit`: https://phpunit.de/
+.. _`PHPSpec`: https://www.phpspec.net/
 .. _`smoke testing`: https://en.wikipedia.org/wiki/Smoke_testing_(software)
 .. _`Mink`: http://mink.behat.org
 .. _`HautelookAliceBundle`: https://github.com/hautelook/AliceBundle