ci: fix mistakes in .gitlab-ci.yml

Refs #55

.gitlab-ci.yml

@@ -37,12 +37,12 @@ build_patched:
 check_not_cran_patched:
   variables:
     R_VERSION: "patched"
-    extends: .check_not_cran
+  extends: .check_not_cran
 
 check_as_cran_patched:
   variables:
     R_VERSION: "patched"
-    extends: .check_as_cran
+  extends: .check_as_cran
 
 build_devel:
   only:
@@ -54,20 +54,22 @@ build_devel:
   extends: .build
 
 check_not_cran_devel:
+  only:
     refs:
       - tags
       - schedules
   variables:
     R_VERSION: "devel"
-    extends: .check_not_cran
+  extends: .check_not_cran
 
 check_as_cran_devel:
+  only:
     refs:
       - tags
       - schedules
   variables:
     R_VERSION: "devel"
-    extends: .check_as_cran
+  extends: .check_as_cran
 
 build_oldrel:
   only:
@@ -79,17 +81,19 @@ build_oldrel:
   extends: .build
 
 check_not_cran_oldrel:
+  only:
     refs:
       - tags
       - schedules
   variables:
     R_VERSION: "oldrel"
-    extends: .check_not_cran
+  extends: .check_not_cran
 
 check_as_cran_oldrel:
+  only:
     refs:
       - tags
       - schedules
   variables:
     R_VERSION: "oldrel"
-    extends: .check_as_cran
+  extends: .check_as_cran