Update Travis config

.travis.yml

@@ -1,9 +1,8 @@
 language: php
 
 php:
-  - 7.2.0
-  - 7.1.3
-  - 7.0.0
+  - 7.3
+  - 7.2
 
 env:
   - PREFER_LOWEST=""
@@ -13,16 +12,10 @@ jobs:
   include:
     - script: composer lint
       name: "Lint code"
-      php: 7.2.0
+      php: 7.3
       env: PREFER_LOWEST=""
 
 script: composer test-ci
 before_script:
   - travis_retry composer self-update
   - travis_retry composer update --no-interaction --prefer-dist $PREFER_LOWEST
-
-before_install:
-  - pip install --user codecov
-
-after_success:
-  - codecov