Changed required version to 3.7 or 5.1 in README (see #7)

Author: Lea Steffen

README.md

@@ -3,7 +3,7 @@ Package for external control of a UR robot. It supports UR3, UR5 and UR10 of CB3
 
 ## prerequisites
 As this URCap is using swing to implement the user interface, the URCap library in version 1.3.0 or
-higher is required. Therefore the minimal PolyScope versions are 3.6 and 5.0.
+higher is required. Therefore the minimal PolyScope versions are 3.7 and 5.1.
 
 To enable external control of a UR robot from a remote PC, this URcap must be installed on the UR robot and the ur\_rtde\_driver has to be installed on the remote PC.