feat: decrypt ! from a

Author: vbetsch

src/main/java/io/github/vbetsch/codecracker/CodeCracker.java

@@ -2,4 +2,7 @@
 
 public class CodeCracker {
 
+    public char decrypt(char a) {
+        return '!';
+    }
 }

src/test/java/io/github/vbetsch/codecracker/CodeCrackerTest.java

@@ -1,16 +1,20 @@
 package io.github.vbetsch.codecracker;
 
 import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 class CodeCrackerTest {
 
     @Test
-    void should_doSomething_whenSomeCondition() {
+    void should_returnExclamationPoint_whenDecryptLetterA() {
         // Arrange
         CodeCracker codeCracker = new CodeCracker();
 
         // Act
+        char decryptedLetterA = codeCracker.decrypt('a');
+
         // Assert
+        assertEquals('!', decryptedLetterA);
     }
 
 }