Pass shellcheck, more specs are handled, preserve function whitespace

This closes #49.

tests/variable

@@ -2,8 +2,8 @@
 cd "${0%/*}" || exit 1
 . ../run-tests
 
-foo=bar
-template="{{#foo}}{{.}} is {{foo}}{{/foo}}"
-expected="bar is bar"
+export foo=bar
+export template="{{#foo}}{{.}} is {{foo}}{{/foo}}"
+export expected="bar is bar"
 
 runTest