[skip ci] small changes in ci_templates

.ci_templates/.install_core.yml

 .install_wolf_script:
+  - cd ${CI_PROJECT_DIR}
+
+  # create 'ci_deps' folder (if not exists)
+  - mkdir -pv ci_deps
+
+  # clone or pull
   - cd ${CI_PROJECT_DIR}/ci_deps
   - if [ -d wolf ]; then
   -   echo "directory wolf exists"
@@ -10,6 +16,8 @@
   -   git clone -b $WOLF_CORE_BRANCH ssh://git@gitlab.iri.upc.edu:2202/mobile_robotics/wolf_projects/wolf_lib/wolf.git
   -   cd wolf
   - fi
+
+  # build and install
   - mkdir -pv build
   - cd build
   - cmake -DCMAKE_BUILD_TYPE=release -DBUILD_DEMOS=OFF -DBUILD_TESTS=OFF ..