Initialize ERROR_ON_CLONE flag in grenaderc

A user can set ERROR_ON_CLONE to yes (true) to fail a run if a git
clone fails.  This patch will document that behavior in grenaderc
and set the flag to its default value of no (unless a user overrides).

Change-Id: I1b1f80b00b4a4838ef10241306d9190520a93701

grenaderc

@@ -64,6 +64,10 @@ ENABLE_TEMPEST=${ENABLE_TEMPEST:-True}
 # We need RECLONE to get the updated branches; not everyone wants it though
 RECLONE=${RECLONE:-no}
 
+# Set this to True if you want to abort execution with an error if a git repo
+# does not exist
+ERROR_ON_CLONE=${ERROR_ON_CLONE:-False}
+
 # Allow only running parts of this script
 RUN_BASE=${RUN_BASE:-True}
 RUN_TARGET=${RUN_TARGET:-True}

inc/bootstrap

@@ -106,6 +106,8 @@ function git_clone {
     local git_clone_flags=""
 
     RECLONE=$(trueorfalse False RECLONE)
+    ERROR_ON_CLONE=$(trueorfalse False ERROR_ON_CLONE)
+
     if [[ "${GIT_DEPTH}" -gt 0 ]]; then
         git_clone_flags="$git_clone_flags --depth $GIT_DEPTH"
     fi