Merge pull request #46 from SignpostMarv/travis/7.4-testing

travis 7.4 testing

Author: weirdan

.travis.yml

@@ -3,9 +3,10 @@ php:
     - 7.1
     - 7.2
     - 7.3
-#    - 7.4snapshot # Psalm does not support 7.4 yet (uses Fn)
+    - 7.4 # Psalm does not support 7.4 yet (uses Fn)
 before_install:
     - phpenv config-rm xdebug.ini || true
+    - composer clear-cache
 
 install:
   - composer install