add generate command to applications (#27)

- Add a infrastructure layer with interfaces for accessing filesystem and reading the clock
- Add a GenerateCommand to execute generation
- Add columnName where needed
- Add DiffDeque with domain logic related to the array of diffs.

Makefile

@@ -41,4 +41,7 @@ release:
 		release --rm-dist
 
 mock:
-	@mockgen -source=domain/driver.go -destination=domain/driver_mock.go -package=domain
+	@mockgen -source=domain/driver.go -destination=domain/driver_mock.go -package=domain
+	@mockgen -source=infrastructure/clock.go -destination=infrastructure/clock_mock.go -package=infrastructure
+	@mockgen -source=infrastructure/file.go -destination=infrastructure/file_mock.go -package=infrastructure
+	@mockgen -source=applications/migrationscripts.go -destination=applications/migrationscripts_mock.go -package=applications

applications/application_suite_test.go

@@ -0,0 +1,16 @@
+package applications
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestApplication(t *testing.T) {
+	_t = t
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Application Test Suite")
+}
+
+var _t *testing.T