Add initial windows support (purescript#48)

* Fixes stack build on windows

Stack can't resolve dependencies correctly,
recommended action was to add this line
to stack.yaml.

This may be better fixed upstream in turtle,
as it seems stack comes with a newer version
of win32 than turtle supports

* Fixes bundle on windows

The quotes caused issues on windows. Purs would
complain about having no files.

Changing the quote style fixes the command
on windows

app/Spago.hs

@@ -278,7 +278,7 @@ bundle withMain maybeModuleName maybeTargetPath = do
         WithoutMain -> ""
 
       cmd
-        = "purs bundle './output/*/*.js'"
+        = "purs bundle \"output/*/*.js\""
         <> " -m " <> moduleName
         <> main
         <> " -o " <> targetPath

stack.yaml

@@ -9,3 +9,4 @@ extra-deps:
 - repline-0.2.0.0
 - async-pool-0.9.0.2
 - serialise-0.2.1.0
+- Win32-2.5.4.1@sha256:e623a1058bd8134ec14d62759f76cac52eee3576711cb2c4981f398f1ec44b85