bug #999 Unify audience claim (aerrasti)

This PR was merged into the 2.x branch.

Discussion
----------

Unify audience claim

The 'aud' part of the payload is being converted to array, thats why we need to use UnifyAudience claim formatter to create lcobucci token.

Before the change:
```json
{
  "iss": "iss",
  "aud": [
     "audience"
  ],
  "sub": "sub",
}
```
After the change
```json
{
  "iss": "iss",
  "aud": "audience",
  "sub": "sub",
}
```
Check out the `default` method:

https://github.com/lcobucci/jwt/blob/4.2.x/src/Encoding/ChainedFormatter.php

:)

Commits
-------

666b1ce Unify audience claim

Services/JWSProvider/LcobucciJWSProvider.php

@@ -4,8 +4,8 @@
 
 use Lcobucci\Clock\SystemClock;
 use Lcobucci\JWT\Builder;
+use Lcobucci\JWT\Encoding\ChainedFormatter;
 use Lcobucci\JWT\Encoding\JoseEncoder;
-use Lcobucci\JWT\Encoding\MicrosecondBasedDateConversion;
 use Lcobucci\JWT\Parser;
 use Lcobucci\JWT\Signer;
 use Lcobucci\JWT\Signer\Hmac;
@@ -87,7 +87,7 @@ public function __construct(KeyLoaderInterface $keyLoader, string $cryptoEngine,
     public function create(array $payload, array $header = [])
     {
         if (class_exists(JWTBuilder::class)) {
-            $jws = new JWTBuilder(new JoseEncoder(), new MicrosecondBasedDateConversion());
+            $jws = new JWTBuilder(new JoseEncoder(), ChainedFormatter::default());
         } else {
             $jws = new Builder();
         }