Update .travis.yml

Author: Nyholm

.travis.yml

@@ -9,7 +9,6 @@ cache:
 php:
     - 7.0
     - 7.1
-    - hhvm
 
 env:
     global:
@@ -22,7 +21,7 @@ branches:
 matrix:
     fast_finish: true
     include:
-        - php: 5.5
+        - php: 7.0
           env: COMPOSER_FLAGS="--prefer-stable --prefer-lowest" COVERAGE=true TEST_COMMAND="composer test-ci"
 
 before_install: