add note about php < 7.1

Author: fab2s

README.md

@@ -14,6 +14,8 @@ composer require "fab2s/bom"
 
 `Bom` is also included in [OpinHelper](https://github.com/fab2s/OpinHelpers) which packages several bellow "Swiss Army Knife" level Helpers covering some of the most annoying aspects of php programing, such as UTF8 string manipulation, high precision Mathematics or properly locking a file
 
+Should you need to work with php bellow 7.1, you can still use [OpinHelper](https://github.com/fab2s/OpinHelpers) `0.x`
+
 ## Prerequisites
 
 `Bom` has no specific dependencies 

composer.json

@@ -36,5 +36,13 @@
         "psr-4": {
             "fab2s\\Tests\\": "tests/"
         }
+    },
+    "scripts": {
+        "post-update-cmd": [
+            "rm -f .*.cache"
+        ],
+        "post-install-cmd": [
+            "rm -f .*.cache"
+        ]
     }
 }