Test all the things!

This merge request improves the code coverage of the project's unit tests.

I broke up this rather large set of changes into separate commits. See the individual commit messages for details.

• 75773b6d - Use PHPUnit provided by Composer instead of downloading a PHAR
• 737771f2 - Convert dashes to underscores when converting to HTTP headers
• 08aaa966 - Group conditional logic for clarity
• 1477621c - Create missing tests for PreauthUserDetailsProvider, introduce an EnvironmentHelper
• b74fd618 - Federated preauth tests made consistent with new preauth tests, improved coverage, moved test data from JSON to source code
• 09d36d36 - LocalUserDetailsProvider throws Exception if JSON is invalid, returns null if JSON is missing
• d021fd72 - Verify missing attributes are set as false
• e29430a9 - Docblock and PSR-2 formatting improvements

PHP Trait

In 1477621c, I introduced a lesser-known feature of PHP called a trait. It allows one to "inject" common methods into any class without requiring inheritance.

@andrew-summers @weizhong-wang @KJOYNER

build.xml

@@ -33,22 +33,8 @@
     </target>
 
     <!-- Runs PHPUnit -->
-    <target name="test" depends="get-phpunit">
-        <exec command="php phpunit.phar" passthru="true" checkreturn="true"/>
-    </target>
-
-    <!-- Downloads PHPUnit -->
-    <target name="get-phpunit">
-        <if>
-            <not>
-                <available file="phpunit.phar"/>
-            </not>
-            <then>
-                <httpget dir="${project.basedir}"
-                         url="https://phar.phpunit.de/phpunit.phar"
-                         followRedirects="true"/>
-            </then>
-        </if>
+    <target name="test">
+        <exec command="php vendor/bin/phpunit" passthru="true" checkreturn="true"/>
     </target>
 
     <target name="release">