refactor: removed version from composer.json

composer.json

 {
-  "name": "quiqqer/discount",
-  "type": "quiqqer-plugin",
-  "description": "Discounts",
-  "version": "dev-master",
-  "license": [
-    "PCSG QEL-1.0"
-  ],
-  "authors": [
-    {
-      "name": "Henning Leutz",
-      "email": "leutz@pcsg.de",
-      "homepage": "http://www.pcsg.de",
-      "role": "Developer"
+    "name": "quiqqer\/discount",
+    "type": "quiqqer-plugin",
+    "description": "Discounts",
+    "license": [
+        "PCSG QEL-1.0"
+    ],
+    "authors": [
+        {
+            "name": "Henning Leutz",
+            "email": "leutz@pcsg.de",
+            "homepage": "http:\/\/www.pcsg.de",
+            "role": "Developer"
+        }
+    ],
+    "support": {
+        "email": "support@pcsg.de",
+        "url": "http:\/\/www.pcsg.de"
+    },
+    "require": {
+        "php": ">=5.3",
+        "quiqqer\/quiqqer": "*@dev",
+        "quiqqer\/areas": "*@dev",
+        "quiqqer\/products": "*@dev",
+        "quiqqer\/tax": "*@dev"
+    },
+    "autoload": {
+        "psr-4": {
+            "QUI\\ERP\\Discount\\": "src\/QUI\/ERP\/Discount",
+            "QUITests\\ERP\\Discount\\": "tests\/QUITests\/ERP\/Discount"
+        }
     }
-  ],
-  "support": {
-    "email": "support@pcsg.de",
-    "url": "http://www.pcsg.de"
-  },
-  "require": {
-    "php": ">=5.3",
-    "quiqqer/quiqqer": "*@dev",
-    "quiqqer/areas": "*@dev",
-    "quiqqer/products": "*@dev",
-    "quiqqer/tax": "*@dev"
-  },
-  "autoload": {
-    "psr-4": {
-      "QUI\\ERP\\Discount\\": "src/QUI/ERP/Discount",
-      "QUITests\\ERP\\Discount\\": "tests/QUITests/ERP/Discount"
-    }
-  }
-}
+}
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