Bump circleci php version

.circleci/config.yml

@@ -29,14 +29,14 @@ jobs:
       - restore_cache:
           keys:
           # "composer.lock" can be used if it is committed to the repo
-          - v1-dependencies-{{ checksum "composer.json" }}
+          - v2-dependencies-{{ checksum "composer.json" }}
           # fallback to using the latest cache if no exact match is found
-          - v1-dependencies-
+          - v2-dependencies-
 
       - run: composer install -n --prefer-dist
 
       - save_cache:
-          key: composer-v1-{{ checksum "composer.lock" }}
+          key: composer-v2-{{ checksum "composer.lock" }}
           paths:
             - vendor