travis: added PHP 7.4

Author: dg

.travis.yml

@@ -3,6 +3,7 @@ php:
     - 7.1
     - 7.2
     - 7.3
+    - 7.4
 
 before_install:
     # turn off XDebug

readme.md

@@ -22,6 +22,8 @@ RobotLoader is a tool that gives you comfort of automated class loading for your
 
 RobotLoader is incredibly comfortable and addictive!
 
+It requires PHP version 7.1 and supports PHP up to 7.4.
+
 If you like Nette, **[please make a donation now](https://nette.org/donate)**. Thank you!
 
 So we can forget about those famous code blocks: