test: Move test support files to separate dir and keep tests in /test

Signed-off-by: Jacques de Laval <jacques@de-laval.se>

test/tenv/start.sh

@@ -0,0 +1,27 @@
+#!/bin/sh
+
+set -eu
+
+TEST_DIR=$(dirname "$0"../)
+TENV_ROOT="${TENV_ROOT:-$(pwd)/${TEST_DIR}/tenv-root}"
+
+unshare=$(command -v unshare)
+chroot=$(command -v chroot)
+
+export PS1='\w \$ '
+export PS2='> '
+export PS3='#? '
+export PS4='+ '
+
+PATH="$TESTENV_PATH"
+export PATH
+
+# Not supported by Busybox unshare:
+#  --cgroup --time
+exec "$unshare" \
+    --user --map-root-user \
+    --fork --pid --mount-proc \
+    --mount \
+    --mount-proc \
+    --uts --ipc --net \
+    "$chroot" "$TENV_ROOT" /bin/chrootsetup.sh "$@"