Complete "longest common ..." examples (#100)

* no else return

* fix var ref

* fix importing/requiring dependencies

* complete longest common examples

03_recursion/Golang/01_countdown/Countdown.go

@@ -6,9 +6,9 @@ func countdown(i int) {
 	fmt.Println(i)
 	if i <= 0 {
 		return
-	} else {
-		countdown(i - 1)
 	}
+
+	countdown(i - 1)
 }
 
 func main() {

03_recursion/Golang/03_factorial/Factorial.go

@@ -5,9 +5,9 @@ import "fmt"
 func fact(x int) int {
 	if x == 1 {
 		return 1
-	} else {
-		return x * fact(x-1)
 	}
+
+	return x * fact(x-1)
 }
 
 func main() {