Update README.md

Author: szczepanmasny

README.md

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 <p align="center">
-  <img width="460" height="300" src="https://user-images.githubusercontent.com/18534115/49319435-29ccf000-f4fd-11e8-9fc6-8678864132bd.png">
+  <img width="300" height="auto" src="https://user-images.githubusercontent.com/18534115/49319435-29ccf000-f4fd-11e8-9fc6-8678864132bd.png">
 </p>
 
 # Vue - based REST-ful CRUD application