Empty 'gitops' folder before git clone command (#49)

When a build agent uses the same workspace for multi stage the gitops folder is not empty
after first stage. I.e.  git clone ${origin} gitops fails due to not empty folder
* Change to use mktmp folder for gitops repo cloning

vars/acePushConfigToGit.groovy

@@ -4,6 +4,7 @@ void call(Map opts = [:]) {
 
   target = readYaml file: 'target-data/target.yaml'
   cfg = readYaml file: opts.aceFile ?: 'ace.yaml'
+  sh "gitOpsfolder=$(mktemp -d gitOpsXXXXXX)"
   Map gitops = cfg.gitops ?: [:]
   String gitopsRepo = gitops.repo
   String strategy = gitops.strategy ?: 'path'
@@ -32,25 +33,25 @@ void call(Map opts = [:]) {
     git config --global user.email jenkins@tietoevry.com
     git config --global user.name "Jenkins the autonomous"
 
-    git clone ${origin} gitops
-    cd gitops
+    git clone ${origin} ${gitOpsfolder}
+    cd ${gitOpsfolder}
     git fetch -a
     """
 
     if (strategy == 'branch') {
       String pushToBranch = gitops.pushToBranch ?: 'test'
 
       String branches = sh(
-        script: 'cd gitops; git branch -a', returnStdout: true).trim()
+        script: 'cd ${gitOpsfolder}; git branch -a', returnStdout: true).trim()
       println "[ace] Got branches ${branches}"
       Boolean branchExists = branches.contains("remotes/origin/${pushToBranch}")
       println "[ace] Branch ${pushToBranch} exists."
 
       gitCheckoutArgs = branchExists ? '' : '-b'
-      sh "cd gitops; git checkout ${gitCheckoutArgs} ${pushToBranch}"
+      sh "cd ${gitOpsfolder}; git checkout ${gitCheckoutArgs} ${pushToBranch}"
 
       sh """
-      cd gitops
+      cd ${gitOpsfolder}
       CHANGED=''
       [ ! -d "${target.name}" ] && {
         cp -R ../target-data ${target.name}
@@ -77,7 +78,7 @@ void call(Map opts = [:]) {
       String targetFolder = "${target.name}/${firstEnv}"
 
       sh """
-      cd gitops
+      cd ${gitOpsfolder}
 
       CHANGED=''
       [ ! -d "${targetFolder}" ] && {