travis support latest php as 8.0 now

.travis.yml

@@ -12,7 +12,7 @@ php:
     - 7.2
     - 7.3
     - 7.4
-    - nightly
+    - 8.0
 
 matrix:
     include:
@@ -24,7 +24,7 @@ matrix:
           dist: trusty
         - php: 7.0
           env: COVERAGE=1
-        - php: nightly
+        - php: 8.0
           env: DEPENDENCIES="--ignore-platform-reqs"
     exclude:
         - php: 5.3
@@ -34,7 +34,7 @@ matrix:
         - php: 5.5
           dist: xenial
     allow_failures:
-        - php: nightly
+        - php: 8.0
 
 cache:
     directories: