Updated to offical travis php 7.4

.travis.yml

@@ -7,7 +7,7 @@ php:
   - 5.6
   - 7.2
   - 7.3
-  - '7.4snapshot'
+  - 7.4
 
 env:
   matrix:
@@ -44,12 +44,12 @@ matrix:
       env: CODECOVERAGE=1 DEFAULT=0
 
   allow_failures:
-    - php: '7.4snapshot'
+    - php: 7.4
 
 before_install:
   - echo cakephp version && tail -1 VERSION.txt
   - |
-      if [[ ${TRAVIS_PHP_VERSION} != "7.4snapshot" ]]; then
+      if [[ ${TRAVIS_PHP_VERSION} != "7.4" ]]; then
         phpenv config-rm xdebug.ini
       fi