Update sponsors on README.md (#271)

This commit remove old sponsors on the readme.

Author: pythonbrad

README.md

@@ -117,6 +117,4 @@ If you like this project, please star and share our repositories. If you feel ge
 
 ### Our sponsors
 
-<a href="https://www.kasahorow.com">
-    <img src="https://www.kasahorow.com/kasahorow_com.png" width="238">
-</a>
+We are open for sponsors.