Remove 'new' keyword when creating case class

Remove 'new' keyword when creating instances of case class
in 'Lower type bounds' section.

Author: Mõškovski Stanislav

_ba/tour/lower-type-bounds.md

@@ -68,6 +68,6 @@ case class EuropeanSwallow() extends Bird
 
 val africanSwallowList= ListNode[AfricanSwallow](AfricanSwallow(), Nil())
 val birdList: Node[Bird] = africanSwallowList
-birdList.prepend(new EuropeanSwallow)
+birdList.prepend(EuropeanSwallow())
 ```
 `Node[Bird]` može biti dodijeljena `africanSwallowList` ali onda prihvatiti `EuropeanSwallow`e.

_ja/tour/lower-type-bounds.md

@@ -69,7 +69,7 @@ case class EuropeanSwallow() extends Bird
 
 val africanSwallowList= ListNode[AfricanSwallow](AfricanSwallow(), Nil())
 val birdList: Node[Bird] = africanSwallowList
-birdList.prepend(new EuropeanSwallow)
+birdList.prepend(EuropeanSwallow())
 ```
 `Node[Bird]`は`africanSwallowList`をアサインできますが、その後`EuropeanSwallow`を受け入れられます。
 

_ru/tour/lower-type-bounds.md

@@ -65,6 +65,6 @@ case class EuropeanSwallow() extends Bird
 
 val africanSwallowList= ListNode[AfricanSwallow](AfricanSwallow(), Nil())
 val birdList: Node[Bird] = africanSwallowList
-birdList.prepend(new EuropeanSwallow)
+birdList.prepend(EuropeanSwallow())
 ```
 `Node[Bird]` может быть присвоен `africanSwallowList` , но затем может добавлять и `EuropeanSwallow`.

_tour/lower-type-bounds.md

@@ -62,6 +62,6 @@ case class EuropeanSwallow() extends Bird
 
 val africanSwallowList= ListNode[AfricanSwallow](AfricanSwallow(), Nil())
 val birdList: Node[Bird] = africanSwallowList
-birdList.prepend(new EuropeanSwallow)
+birdList.prepend(EuropeanSwallow())
 ```
 The `Node[Bird]` can be assigned the `africanSwallowList` but then accept `EuropeanSwallow`s.

_zh-cn/tour/lower-type-bounds.md

@@ -62,6 +62,6 @@ case class EuropeanSwallow() extends Bird
 
 val africanSwallowList= ListNode[AfricanSwallow](AfricanSwallow(), Nil())
 val birdList: Node[Bird] = africanSwallowList
-birdList.prepend(new EuropeanSwallow)
+birdList.prepend(EuropeanSwallow())
 ```
 可以为 `Node[Bird]` 赋值 `africanSwallowList`，然后再加入一个 `EuropeanSwallow`。