Revert "Update .gitlab-ci.yml"

This reverts commit a7058149

.gitlab-ci.yml

@@ -6,6 +6,8 @@ stages:
 
 Lint:
   stage: lint
+  tags:
+    - docker
   image: mwirtz/python2.7-healpy
   script:
     - pip install pylint flake8
@@ -25,6 +27,8 @@ Lint:
 
 Coverage:
     stage: coverage
+    tags:
+        - docker
     image: mwirtz/python2.7-healpy
     script:
         - pip install coverage
@@ -37,6 +41,8 @@ Coverage:
 
 Unittest27:
   stage: unittest
+  tags:
+    - docker
   image: mwirtz/python2.7-healpy
   script:
     - export PYTHONPATH=/builds/astro/astrotools
@@ -52,6 +58,8 @@ Unittest27:
 
 Unittest35:
   stage: unittest
+  tags:
+    - docker
   image: mwirtz/python3.5-healpy
   script:
     - export PYTHONPATH=/builds/astro/astrotools
@@ -67,6 +75,8 @@ Unittest35:
 
 pages:
   stage: deploy
+  tags:
+    - docker
   image: mwirtz/python2.7-healpy
   script:
     - pip install sphinx sphinx-rtd-theme sphinxcontrib-websupport