Remove PHP-nightly from travis-ci config

Author: codemedic

.travis.yml

@@ -21,9 +21,9 @@ matrix:
       dist: bionic
     - php: 7.4
       dist: bionic
-    - php: nightly
-      dist: bionic
-      env: COMPOSER_ARGS=--ignore-platform-reqs
+#    - php: nightly
+#      dist: bionic
+#      env: COMPOSER_ARGS=--ignore-platform-reqs
 
 before_script:
   - composer self-update --stable

composer.json

@@ -9,7 +9,7 @@
     "ext-bcmath": "*"
   },
   "require-dev": {
-    "phpunit/phpunit": "*",
+    "phpunit/phpunit": "^4",
     "symfony/polyfill-php72": "^1.18",
     "victorjonsson/markdowndocs": "^1.3"
   },