Update circleci config

Author: aamsur

.circleci/config.yml

@@ -19,8 +19,6 @@ jobs:
     steps:
       - checkout
 
-      - run: composer self-update
-
       # Download and cache dependencies
       - restore_cache:
           keys:
@@ -36,4 +34,4 @@ jobs:
             - vendor
 
       # run tests!
-      - run: php vendor/bin/phpunit --colors --debug  --coverage-text
+      - run: php vendor/bin/phpunit --colors --debug  --coverage-text