RKorAPClient requires R version >= 3.5

Change-Id: If9f7afd0254578cc1026ef6f6158db32ecee0e86
diff --git a/Readme.md b/Readme.md
index b5a69fe..2ef1c9d 100644
--- a/Readme.md
+++ b/Readme.md
@@ -13,7 +13,7 @@
 via [rpy2](https://rpy2.github.io/). **Please note that with a native implementation the API might change.**
 
 ## Installation
-#### 1. Install  R
+#### 1. Install R (version >= 3.5)
 From [CRAN](https://cran.r-project.org/bin/) or, alternatively, on some recent Linux distributions: 
 
 ```shell script