Fix warnings about unused setup and teardown

asynctest.nim

@@ -4,12 +4,12 @@ export unittest except suite, test
 template suite*(name, body) =
   suite name:
 
-    template setup(setupBody) =
+    template setup(setupBody) {.used.} =
       setup:
         let asyncproc = proc {.async.} = setupBody
         waitFor asyncproc()
 
-    template teardown(teardownBody) =
+    template teardown(teardownBody) {.used.} =
       teardown:
         let asyncproc = proc {.async.} = teardownBody
         waitFor asyncproc()

asynctest.nimble

@@ -1,4 +1,4 @@
-version = "0.2.0"
+version = "0.2.1"
 author = "asynctest Authors"
 description = "Test asynchronous code"
 license = "MIT"