Provide minimal test target (#27)

AMDmi3 · jarun · commit 2732132ac88b · 2017-11-29T23:54:30.000+05:30
This at least checks that all imports are satisfied
diff --git a/Makefile b/Makefile
@@ -22,4 +22,5 @@ uninstall:
 	rm -f $(DESTDIR)$(MANDIR)/ddgr.1.gz
 	rm -rf $(DESTDIR)$(DOCDIR)
 
-test: ;
+test:
+	./ddgr --help
