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

src/main/edu/wisc/doit/uwphps/preauth/PreauthUserDetailsProvider.php

@@ -9,7 +9,7 @@ use edu\wisc\doit\uwphps\UWUserDetails;
  * PreauthUserDetailsProvider is an implementation of {@link UserDetailsProvider} for loading users authenticated
  * with UW-Madison login.
  *
- * {@see FederatedPreauthUserDetailsProvider} for loading users authenticated through UW-System Federated login.
+ * See {@link FederatedPreauthUserDetailsProvider} for loading users authenticated through UW-System Federated login.
  */
 class PreauthUserDetailsProvider extends UserDetailsProvider
 {
@@ -23,9 +23,6 @@ class PreauthUserDetailsProvider extends UserDetailsProvider
     const FIRST_NAME = 'givenName';
     const LAST_NAME = 'sn';
 
-    /**
-     * {@inheritdoc}
-     */
     public function loadUser()
     {
         // Return null if no Shib session is found
@@ -62,5 +59,4 @@ class PreauthUserDetailsProvider extends UserDetailsProvider
 
         return $userDetails;
     }
-
 }