Add mock registry prep

src/spectator/mocks.cr

@@ -3,5 +3,11 @@ require "./mocks/*"
 module Spectator
   # Functionality for mocking existing types.
   module Mocks
+    def self.run(context : TestContext)
+      Registry.prepare(context)
+      yield
+    ensure
+      Registry.reset
+    end
   end
 end

src/spectator/mocks/registry.cr

@@ -11,6 +11,10 @@ module Spectator::Mocks
 
     @@entries = {} of Key => Entry
 
+    def prepare(context : TestContext) : Nil
+      # TODO
+    end
+
     def reset : Nil
       @@entries.clear
     end

src/spectator/runnable_example.cr

@@ -7,10 +7,11 @@ module Spectator
     # Runs the example, hooks, and captures the result
     # and translates to a usable result.
     def run_impl : Result
-      result = capture_result
-      expectations = Harness.current.expectations
-      Mocks::Registry.reset
-      translate_result(result, expectations)
+      Mocks.run(group.context) do
+        result = capture_result
+        expectations = Harness.current.expectations
+        translate_result(result, expectations)
+      end
     end
 
     # Runs all hooks and the example code.