format composer.json tabs -> spaces, add ext-mbstring requirement, dep updates

Author: mike42

Diff for: composer.json

@@ -1,26 +1,33 @@
 {
-	"name": "mike42/escpos-php",
-	"type": "library",
-	"description": "PHP receipt printer library for use with ESC/POS-compatible thermal and impact printers",
-	"homepage": "https://github.com/mike42/escpos-php",
-	"keywords": ["receipt", "print", "escpos", "ESC-POS", "driver"],
-	"license": "MIT",
-	"authors": [
-		{
-			"name": "Michael Billington",
-			"email": "[email protected]"
-		}
-	],
-	"require": {
-		"php": ">=5.3.0"
-	},
-	"require-dev": {
-	    "phpunit/phpunit": "4.5.*",
-	    "squizlabs/php_codesniffer": "2.*"
-	},
-	"autoload": {
-		"psr-4": {
-			"Mike42\\": "src/Mike42"
-		}
-	}
+    "name": "mike42/escpos-php",
+    "type": "library",
+    "description": "PHP receipt printer library for use with ESC/POS-compatible thermal and impact printers",
+    "homepage": "https://github.com/mike42/escpos-php",
+    "keywords": ["receipt", "print", "escpos", "ESC-POS", "driver"],
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "Michael Billington",
+            "email": "[email protected]"
+        }
+    ],
+    "config": {
+        "platform": {
+            "php": "5.3.9"
+        }
+    },
+    "require": {
+        "php": ">=5.3.9",
+        "ext-mbstring": "*"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "4.8.*",
+        "squizlabs/php_codesniffer": "2.*"
+    },
+    "autoload": {
+        "psr-4": {
+            "Mike42\\": "src/Mike42"
+        }
+    }
 }
+