Fix more references to old gitlab-runner

doc/ci/docker/using_docker_images.md

@@ -23,7 +23,7 @@ To use GitLab Runner with docker you need to register a new runner to use the
 `docker` executor:
 
 ```bash
-gitlab-runner register \
+gitlab-ci-multi-runner register \
   --url "https://gitlab.com/" \
   --registration-token "PROJECT_REGISTRATION_TOKEN" \
   --description "docker-ruby-2.1" \

doc/ci/examples/php.md

@@ -263,10 +263,10 @@ terminal execute:
 
 ```bash
 # Check using docker executor
-gitlab-runner exec docker test:app
+gitlab-ci-multi-runner exec docker test:app
 
 # Check using shell executor
-gitlab-runner exec shell test:app
+gitlab-ci-multi-runner exec shell test:app
 ```
 
 ## Example project

doc/ci/runners/README.md

@@ -63,7 +63,7 @@ instance.
 Now simply register the runner as any runner:
 
 ```
-sudo gitlab-runner register
+sudo gitlab-ci-multi-runner register
 ```
 
 Shared runners are enabled by default as of GitLab 8.2, but can be disabled with the
@@ -93,7 +93,7 @@ setup a specific runner for this project.
 To register the runner, run the command below and follow instructions:
 
 ```
-sudo gitlab-runner register
+sudo gitlab-ci-multi-runner register
 ```
 
 ###  Making an existing Shared Runner Specific