Add the extra spago file "test.dhall" for testing

package.json

@@ -6,7 +6,7 @@
   "contributors": [],
   "main": "main.js",
   "scripts": {
-    "test": "spago test",
+    "test": "spago -x test.dhall test",
     "postinstall": "spago build"
   },
   "devDependencies": {},

spago.dhall

@@ -3,17 +3,14 @@
 , dependencies =
     [ "argonaut-codecs"
     , "argonaut-core"
-    , "console"
     , "effect"
     , "foreign"
     , "functions"
     , "ordered-collections"
-    , "psci-support"
-    , "spec"
     , "unsafe-coerce"
     ]
 , packages =
     ./packages.dhall
 , sources =
-    [ "src/**/*.purs", "test/**/*.purs" ]
+    [ "src/**/*.purs" ]
 }

test.dhall

@@ -0,0 +1,6 @@
+let conf = ./spago.dhall
+
+in conf // {
+  sources = conf.sources # [ "test/**/*.purs" ],
+  dependencies = conf.dependencies # [ "console", "psci-support", "spec" ]
+}