Run integration tests against the dstask binary produced in the build step.

--- a/integration/main_test.go
+++ b/integration/main_test.go
@@ -6,46 +6,14 @@ import (
 	"log"
 	"os"
 	"os/exec"
-	"runtime"
 	"testing"
 
 	"github.com/naggie/dstask"
 	"gotest.tools/assert"
 )
 
-func TestMain(m *testing.M) {
-	binary := binaryPath()
-
-	if err := compile(binary); err != nil {
-		log.Fatalf("compile error: %v", err)
-	}
-
-	cleanup := func() {
-		if err := os.Remove(binary); err != nil {
-			log.Panicf("could not remove integration test binary %s", binary)
-		}
-	}
-
-	exitCode := m.Run()
-
-	cleanup()
-	os.Exit(exitCode)
-}
-
-func compile(outputPath string) error {
-	// We expect to execute in the ./integration directory, and we will output
-	// our test binary there.
-	cmd := exec.Command("go", "build", "-mod=vendor", "-o", outputPath, "../cmd/dstask/main.go")
-
-	return cmd.Run()
-}
-
 func binaryPath() string {
-	if runtime.GOOS == "windows" {
-		return "./dstask.exe"
-	}
-
-	return "./dstask"
+	return "../bin/dstask"
 }
 
 // Create a callable closure that will run our test binary against a