Add script for starting a vanilla emacs with el-get loaded

Unlike the other test scripts, this doesn't run a test or install a
recipe or anything. It just opens up emacs with el-get ready to go so
you can do manual testing.

test/test-interactive.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+set_default () {
+  eval "
+if [ -z \$$1 ]; then
+  $1=$2
+fi
+"
+}
+
+set_default EL_GET_LIB_DIR "$(dirname "$(dirname "$(readlink -f "$0")")")"
+set_default TMPDIR "$(dirname "$(mktemp --dry-run)")"
+set_default TEST_HOME "$TMPDIR/el-get-test-home"
+set_default EMACS "$(which emacs)"
+
+mkdir -p "$TEST_HOME"/.emacs.d
+rm -rf "$TEST_HOME"/.emacs.d/el-get/
+HOME="$TEST_HOME" "$EMACS" -Q -L "$EL_GET_LIB_DIR" \
+  -l "$EL_GET_LIB_DIR/el-get.el" -l "$EL_GET_LIB_DIR/test/test-setup.el"