Fix MagicianInTraining testRemoveBottomCardFromEmptyStack

Instead of `removeBottomCard` `removeTopCard` was called in the test.

exercises/concept/magician-in-training/Tests/MagicianInTrainingTests/MagicianInTrainingTests.swift

@@ -86,7 +86,7 @@ final class MagicianInTrainingTests: XCTestCase {
   func testRemoveBottomCardFromEmptyStack() throws {
     try XCTSkipIf(true && !runAll)  // change true to false to run this test
     let stack = [Int]()
-    XCTAssertEqual(removeTopCard(stack), stack)
+    XCTAssertEqual(removeBottomCard(stack), stack)
   }
 
   func testCheckSizeTrue() throws {