Update install of system requirements

.gitlab-ci.yml

@@ -26,7 +26,7 @@ workflow:
     - python -m pip install --upgrade pip 
     - python -m pip install --upgrade conan 
     # Install prerequisite for git-gui and gitk
-    - sudo yum install tcl-devel tk-devel
+    - sudo yum -y install tcl-devel tk-devel
     # Build git with conan
     - conan profile detect --force
     - conan create . --version ${GIT_VERSION} -s compiler.libcxx=libstdc++11 --build="*"