add Music#chord (#204)

src/main/java/com/github/javafaker/Music.java

@@ -4,6 +4,7 @@ public class Music {
 
     private static final String[] KEYS = new String[] { "C", "D", "E", "F", "G", "A", "B" };
     private static final String[] KEY_VARIANTS = new String[] { "b", "#", "" };
+    private static final String[] CHORD_TYPES = new String[] { "", "maj", "6", "maj7", "m", "m7", "-7", "7", "dom7", "dim", "dim7", "m7b5"};
 
     private final Faker faker;
 
@@ -18,4 +19,8 @@ public class Music {
     public String key() {
         return faker.options().option(KEYS) + faker.options().option(KEY_VARIANTS);
     }
+
+    public String chord() {
+        return key() + faker.options().option(CHORD_TYPES);
+    }
 }

src/test/java/com/github/javafaker/MusicTest.java

@@ -16,4 +16,9 @@ public class MusicTest extends AbstractFakerTest {
     public void key() {
         assertThat(faker.music().key(), matchesRegularExpression("([A-Z])+(b|#){0,1}"));
     }
+
+    @Test
+    public void chord() {
+        assertThat(faker.music().chord(), matchesRegularExpression("([A-Z])+(b|#){0,1}+(-?[a-zA-Z0-9]{0,4})"));
+    }
 }