added more aviation tests

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

@@ -1,17 +1,25 @@
 package com.github.javafaker;
 
-import com.github.javafaker.repeating.Repeat;
 import org.junit.Test;
 
+import static com.github.javafaker.matchers.IsStringWithContents.isStringWithContents;
 import static com.github.javafaker.matchers.MatchesRegularExpression.matchesRegularExpression;
 import static org.junit.Assert.assertThat;
 
 public class AviationTest extends AbstractFakerTest {
 
     @Test
-    @Repeat(times=3)
-    public void testAviation() {
-        String airport = faker.aviation().airport();
-        assertThat(airport, matchesRegularExpression("\\w{4}"));
+    public void airport() {
+        assertThat(faker.aviation().airport(), matchesRegularExpression("\\w{4}"));
     }
-}
+
+    @Test
+    public void aircraft() {
+        assertThat(faker.aviation().aircraft(), isStringWithContents());
+    }
+
+    @Test
+    public void metar() {
+        assertThat(faker.aviation().METAR(), isStringWithContents());
+    }
+}