Fix behavior of interrupt (SIGINT, SIGTERM) signals

Task will now give time for the processes running to do cleanup work

Ref #458
Ref #479
Fixes #728

Co-authored-by: Marco Molteni <marco.molteni@pix4d.com>
Co-authored-by: aliculPix4D <aleksandar.licul_ext@pix4d.com>

signals.go

@@ -0,0 +1,31 @@
+package task
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/go-task/task/v3/internal/logger"
+)
+
+// NOTE(@andreynering): This function intercepts SIGINT and SIGTERM signals
+// so the Task process is not killed immediatelly and processes running have
+// time to do cleanup work.
+func (e *Executor) InterceptInterruptSignals() {
+	ch := make(chan os.Signal, 3)
+	signal.Notify(ch, os.Interrupt, syscall.SIGTERM)
+
+	go func() {
+		for i := 1; i <= 3; i++ {
+			sig := <-ch
+
+			if i < 3 {
+				e.Logger.Outf(logger.Yellow, `task: Signal received: "%s"`, sig)
+				continue
+			}
+
+			e.Logger.Errf(logger.Red, `task: Signal received for the third time: "%s". Forcing shutdown`, sig)
+			os.Exit(1)
+		}
+	}()
+}