Adding readme file and update the requirements

README.md

@@ -0,0 +1,21 @@
+# Botman Studio installer
+
+First, download the BotMan installer using Composer:
+
+```
+composer global require "botman/installer"
+```
+
+Make sure to place the `$HOME/.composer/vendor/bin directory` 
+(or the equivalent directory for your OS) in your `$PATH` so the botman executable can be located by your system. 
+
+Once installed, the botman new command will create a fresh BotMan Studio installation in the directory you specify.
+
+For instance, `botman new weatherbot` will create a directory named `weatherbot` containing a fresh BotMan Studio 
+installation with all of BotMan's dependencies already installed:
+
+```
+botman new weatherbot
+```
+
+Take a look at the [BotMan Studio documentation](https://botman.io/2.0/botman-studio), to learn more about how to add and configure messaging drivers.

composer.json

@@ -17,9 +17,9 @@
     "require": {
         "ext-zip": "*",
         "guzzlehttp/guzzle": "~4.0|~5.0|~6.0",
-        "symfony/console": "~2.3|~3.0",
-        "symfony/filesystem": "~2.3|~3.0",
-        "symfony/process": "~2.3|~3.0"
+        "symfony/console": "~2.3|~3.0|~4.0",
+        "symfony/filesystem": "~2.3|~3.0|~4.0",
+        "symfony/process": "~2.3|~3.0|~4.0"
     },
     "bin": [
         "botman"