Update Installation section of readme with Dist::Zilla build commands

As best I understand it, Dist::Zilla replaces the make stuff entirely,
so the readme should reflect that.

README

@@ -15,10 +15,9 @@ INSTALLATION
 
 To install this module, run the following commands:
 
-	perl Makefile.PL
-	make
-	make test
-	make install
+       dzil build
+       dzil test
+       dzil install
 
 UNIT TESTS