Add initial support for PHP7 (#97)

* Add initial support for PHP7

* Update PHP env with now an PSR3 logger (Monolog). Now you can also create a handler function with PSR7 Http message and PSR3 logger in parameter.

* Add examples for PHP7 environement

* For development you can create a function in this path /app/userfuncdev.php it will be loaded

* Switch to alpine base image

* handler now receive an array with request, response and logger object

environments/php7/src/Server.php

@@ -0,0 +1,64 @@
+<?php
+
+namespace PHPEnv;
+
+use Monolog\Logger;
+use Monolog\Handler\StreamHandler;
+use Zend\Diactoros\ServerRequest;
+use Zend\Diactoros\Response;
+use Zend\Diactoros\Server as ZendServer;
+
+class Server {
+    private $server;
+
+    public function __construct(){
+        $codepath = '/userfunc/user';
+
+        //if i have a local function i use it
+        $devcodepath = '/app/userfuncdev.php';
+        if(file_exists($devcodepath))
+            $codepath = $devcodepath;
+
+        $logger = new Logger("Function");
+        $logger->pushHandler(new StreamHandler('php://stdout', Logger::DEBUG));
+
+        $this->server = ZendServer::createServer(
+            function (ServerRequest $request, Response $response) use ($logger, $codepath) {
+                $path = parse_url($request->getUri(), PHP_URL_PATH);
+
+                if($path == "/specialize" && $request->getMethod() == "POST"){
+                    //Nothing to do
+                    return new Response\EmptyResponse(201);
+                }else{
+                    if(!file_exists($codepath)){
+                        $response = $response->withStatus(500);
+                        $response->getBody()->write("Generic container: no requests supported");
+                        return $response;
+                    }
+
+                    ob_start();
+                    include($codepath);
+                    //If the function as an handler class it will be called with request, response and logger
+                    if(function_exists("handler")){
+                        ob_end_clean();
+                        return handler(array("request"=>$request, "response"=>$response,"logger"=>$logger));
+                    }
+                    //php code didn't have handler function, i will return the content
+                    $bodyRowContent = ob_get_contents();
+                    ob_end_clean();
+                    return $response->getBody()->write($bodyRowContent);
+                }
+            },
+            $_SERVER,
+            $_GET,
+            $_POST,
+            $_COOKIE,
+            $_FILES
+        );
+    }
+    
+    public function run(){
+        $this->server->listen();
+    }
+}
+?>