update gitlab ci

.gitlab-ci.yml

@@ -5,8 +5,8 @@ services:
 
 variables:
   POSTGRES_DB: pleroma_test
-  POSTGRES_USER: pleroma
-  POSTGRES_PASSWORD: pleroma
+  POSTGRES_USER: postgres
+  POSTGRES_PASSWORD: postgres
 
 stages:
   - test
@@ -21,4 +21,4 @@ before_script:
 unit-testing:
   stage: test
   script:
-    - MIX_ENV=test mix test
\ No newline at end of file
+    - MIX_ENV=test mix test