Improve code comments

app/models/ci/build.rb

@@ -179,7 +179,7 @@ module Ci
     end
 
     def repo_url
-      auth = "gitlab-ci-token:#{ensure_token}@"
+      auth = "gitlab-ci-token:#{ensure_token!}@"
       project.http_url_to_repo.sub(/^https?:\/\//) do |prefix|
         prefix + auth
       end

app/policies/project_policy.rb

@@ -64,7 +64,7 @@ class ProjectPolicy < BasePolicy
     can! :read_deployment
   end
 
-  # Permissions given when an user is direct member of a group
+  # Permissions given when an user is team member of a project
   def team_member_reporter_access!
     can! :build_download_code
     can! :build_read_container_image

app/services/auth/container_registry_authentication_service.rb

@@ -90,7 +90,7 @@ module Auth
 
     def build_can_pull?(requested_project)
       # Build can:
-      # 1. pull from it's own project (for ex. a build)
+      # 1. pull from its own project (for ex. a build)
       # 2. read images from dependent projects if creator of build is a team member
       @authentication_abilities.include?(:build_read_container_image) &&
         (requested_project == project || can?(current_user, :build_read_container_image, requested_project))
@@ -102,7 +102,7 @@ module Auth
     end
 
     def build_can_push?(requested_project)
-      # Build can push only to project to from which he originates
+      # Build can push only to the project from which it originates
       @authentication_abilities.include?(:build_create_container_image) &&
         requested_project == project
     end