[Slim] Add Basic authentication middleware (#606)

* [Slim] Add Basic Authentication Middleware

User needs to add own implementation to verifyCredentials method in AuthBasic.php.

* [Slim] Update README template

I'm not sure about `middlewareSrcPath` variable. I'll fix it in following PRs
if path is broken.
Hope that notice in README catches attention and most of users will read it.

* Revert "[Slim] Update README template"

This reverts commit 204ee02fd8.

* Revert "[Slim] Add Basic Authentication Middleware"

This reverts commit 6a8e03079a.

* [Slim] Add "tuupola/slim-basic-auth" package

Package "tuupola/slim-basic-auth" 3.1.0 requires PHP 7, that's why I
set it's version to ^3.0.0 in Composer. Minimum version will be
3.0.0-rc.1 which supports PHP 5.5. I've tested build with PHP 7, it
would be nice to check build with PHP 5.5 someday.

* [Slim] Update README template

Not sure about forward slash in path to SlimRouter class. I will fix it
in upcoming PRs if necessary.

* [Slim] Refresh samples

modules/openapi-generator/src/main/resources/php-slim-server/README.mustache

@@ -7,4 +7,16 @@ is an example of building a PHP Slim server.
 
 This example uses the [Slim Framework](http://www.slimframework.com/).  To see how to make this your own, please take a look at the template here:
 
-[TEMPLATES](https://github.com/openapitools/openapi-generator/tree/master/modules/openapi-generator/src/main/resources/slim/)
+[TEMPLATES](https://github.com/openapitools/openapi-generator/tree/master/modules/openapi-generator/src/main/resources/php-slim-server/)
+
+{{#authMethods}}
+{{^hasMore}}
+## Authentication
+{{/hasMore}}
+{{/authMethods}}
+{{#authMethods}}
+{{#isBasic}}
+> Important! To make Basic Authentication work you need to implement `authenticator` function in [SlimRouter]({{srcBasePath}}/SlimRouter.php) class.  
+> Documentation [tuupola/slim-basic-auth](https://github.com/tuupola/slim-basic-auth)
+{{/isBasic}}
+{{/authMethods}}

modules/openapi-generator/src/main/resources/php-slim-server/SlimRouter.mustache

@@ -39,6 +39,7 @@ use {{apiPackage}}\{{classname}};
 use Slim\App;
 use Psr\Container\ContainerInterface;
 use InvalidArgumentException;
+use Tuupola\Middleware\HttpBasicAuthentication;
 
 /**
  * SlimRouter Class Doc Comment
@@ -66,10 +67,29 @@ class SlimRouter {
     public function __construct($container = []) {
         $app = new App($container);
 
+        $basicAuth = new HttpBasicAuthentication([
+            "secure" => false,
+            "authenticator" => function ($arguments) {
+                $user = $arguments["user"];
+                $password = $arguments["password"];
+                return false;
+            }
+        ]);
+
         {{#apis}}
         {{#operations}}
         {{#operation}}
-        $app->{{httpMethod}}('{{{basePathWithoutHost}}}{{{path}}}', {{classname}}::class . ':{{operationId}}');
+        $app->{{httpMethod}}(
+            '{{{basePathWithoutHost}}}{{{path}}}', {{classname}}::class . ':{{operationId}}'
+{{#hasAuthMethods}}
+{{#authMethods}}
+{{#isBasic}}
+        )->add(
+            $basicAuth
+{{/isBasic}}
+{{/authMethods}}
+{{/hasAuthMethods}}
+        );
         {{/operation}}
         {{/operations}}
         {{/apis}}

modules/openapi-generator/src/main/resources/php-slim-server/composer.mustache

@@ -2,7 +2,8 @@
   "minimum-stability": "RC",
   "require": {
     "php": ">=5.5",
-    "slim/slim": "3.*"
+    "slim/slim": "3.*",
+    "tuupola/slim-basic-auth": "^3.0.0"
   },
   "require-dev": {
     "phpunit/phpunit": "^4.8"