Don't run UNIX tests by default.

Makefile

@@ -1,8 +1,20 @@
 # This makefile exists to help run tests.
+#
+# If TEST_UNIX is a non-empty value, runs tests for UNIX sockets. This
+# functionality is not in node-websocket-server at the moment.
 
 .PHONY: test
 
+all: test test-unix
+
 test:
-	for f in `ls -1 test/test-*.js` ; do \
+	for f in `ls -1 test/test-*.js | grep -v unix` ; do \
 		node $$f ; \
 	done
+
+test-unix:
+	if [[ -n "$$TEST_UNIX" ]] ; then \
+		for f in `ls -1 test/test-*.js | grep unix` ; do \
+			node $$f ; \
+		done \
+	fi