Remove TRACK_DEPENDS

This was added in 2012 with I89677fd54635e82b10ab674ddeb9ffb3f1a755f0,
but I can not see it being used anywhere currently.

It's use of virtualenv's has become problematic in a python2
deprecated world, but since it is not used, remove it to avoid further
confusion.

Change-Id: I65d44d24f449436ca6229928eee2c5a021793055
diff --git a/functions-common b/functions-common
index a13d611..6be07b4 100644
--- a/functions-common
+++ b/functions-common
@@ -27,7 +27,6 @@
 # - ``RECLONE``
 # - ``REQUIREMENTS_DIR``
 # - ``STACK_USER``
-# - ``TRACK_DEPENDS``
 # - ``http_proxy``, ``https_proxy``, ``no_proxy``
 #
 
@@ -44,7 +43,6 @@
 declare -A -g GITBRANCH
 declare -A -g GITDIR
 
-TRACK_DEPENDS=${TRACK_DEPENDS:-False}
 KILL_PATH="$(which kill)"
 
 # Save these variables to .stackenv
@@ -2075,11 +2073,7 @@
         return 0
     fi
 
-    if [[ $TRACK_DEPENDS = True ]]; then
-        sudo_cmd="env"
-    else
-        sudo_cmd="sudo"
-    fi
+    sudo_cmd="sudo"
 
     $xtrace
     $sudo_cmd $@