update to build / test instructions from updated test infrastructure

Isweet · Isweet · commit 0598cf323cd8 · 2015-12-29T22:02:21.000-05:00
diff --git a/README.md b/README.md
@@ -12,6 +12,7 @@ book.
     % git clone git@github.com:Isweet/ppa.git
     % cd ppa
     % cabal sandbox init
+    % cabal install --only-dependencies --enable-tests
     % cabal build
     % cabal test
 
