Drop PHP 7.1 on travis

Author: jakzal

.travis.yml

@@ -1,9 +1,8 @@
 language: php
 matrix:
   include:
-  - php: 7.1
-    env: EXECUTE_DEPLOYMENT=true
   - php: 7.2
+    env: EXECUTE_DEPLOYMENT=true
   - php: 7.3
     env: deps=low
   fast_finish: true