Remove Guava and use JUnit assert (#170)

* remove Guava and use JUnit assert

* reassign old to Collection.unmodifiable

* reassign variable expected

exercises/etl/src/test/java/EtlTest.java

-import com.google.common.collect.ImmutableMap;
 import org.junit.Test;
-import org.junit.Ignore;
 
-import java.util.Arrays;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
+
+import static org.junit.Assert.assertEquals;
 
-import static org.assertj.core.api.Assertions.assertThat;
 
 public class EtlTest {
     private final Etl etl = new Etl();
 
-
     @Test
     public void testTransformOneValue() {
-        Map<Integer, List<String>> old = ImmutableMap.of(1, Arrays.asList("A"));
-        Map<String, Integer> expected = ImmutableMap.of("a", 1);
+        Map<Integer, List<String>> old = new HashMap<Integer, List<String>>() {
+            {
+                put(1, Arrays.asList("A"));
+            }
+        };
+        old = Collections.unmodifiableMap(old);
+
+        Map<String, Integer> expected = new HashMap<String, Integer>() {
+            {
+                put("a", 1);
+            }
+        };
+        expected = Collections.unmodifiableMap(expected);
 
-        assertThat(etl.transform(old)).isEqualTo(expected);
+        assertEquals(etl.transform(old), expected);
     }
 
-    @Ignore
     @Test
     public void testTransformMoreValues() {
-        Map<Integer, List<String>> old = ImmutableMap.of(
-                1, Arrays.asList("A", "E", "I", "O", "U")
-        );
-        Map<String, Integer> expected = ImmutableMap.of(
-                "a", 1,
-                "e", 1,
-                "i", 1,
-                "o", 1,
-                "u", 1
-        );
-
-        assertThat(etl.transform(old)).isEqualTo(expected);
+        Map<Integer, List<String>> old = new HashMap<Integer, List<String>>() {
+            {
+                put(1, Arrays.asList("A", "E", "I", "O", "U"));
+            }
+        };
+        old = Collections.unmodifiableMap(old);
+
+        Map<String, Integer> expected = new HashMap<String, Integer>() {
+            {
+                put("a", 1);
+                put("e", 1);
+                put("i", 1);
+                put("o", 1);
+                put("u", 1);
+            }
+        };
+        expected = Collections.unmodifiableMap(expected);
+
+        assertEquals(etl.transform(old), expected);
     }
 
-    @Ignore
     @Test
     public void testMoreKeys() {
-        Map<Integer, List<String>> old = ImmutableMap.of(
-                1, Arrays.asList("A", "E"),
-                2, Arrays.asList("D", "G")
-        );
-        Map<String, Integer> expected = ImmutableMap.of(
-                "a", 1,
-                "e", 1,
-                "d", 2,
-                "g", 2
-        );
-
-        assertThat(etl.transform(old)).isEqualTo(expected);
+        Map<Integer, List<String>> old = new HashMap<Integer, List<String>>() {
+            {
+                put(1, Arrays.asList("A", "E"));
+                put(2, Arrays.asList("D", "G"));
+            }
+        };
+        old = Collections.unmodifiableMap(old);
+
+        Map<String, Integer> expected = new HashMap<String, Integer>() {
+            {
+                put("a", 1);
+                put("e", 1);
+                put("d", 2);
+                put("g", 2);
+            }
+        };
+        expected = Collections.unmodifiableMap(expected);
+
+        assertEquals(etl.transform(old), expected);
     }
 
-    @Ignore
     @Test
     public void testFullDataset() {
-        Map<Integer, List<String>> old = ImmutableMap.<Integer, List<String>>builder().
-                put(1, Arrays.asList("A", "E", "I", "O", "U", "L", "N", "R", "S", "T")).
-                put(2, Arrays.asList("D", "G")).
-                put(3, Arrays.asList("B", "C", "M", "P")).
-                put(4, Arrays.asList("F", "H", "V", "W", "Y")).
-                put(5, Arrays.asList("K")).
-                put(8, Arrays.asList("J", "X")).
-                put(10, Arrays.asList("Q", "Z")).
-                build();
-        Map<String, Integer> expected = ImmutableMap.<String, Integer>builder().
-                put("a", 1).put("b", 3).put("c", 3).put("d", 2).put("e", 1).
-                put("f", 4).put("g", 2).put("h", 4).put("i", 1).put("j", 8).
-                put("k", 5).put("l", 1).put("m", 3).put("n", 1).put("o", 1).
-                put("p", 3).put("q", 10).put("r", 1).put("s", 1).put("t", 1).
-                put("u", 1).put("v", 4).put("w", 4).put("x", 8).put("y", 4).
-                put("z", 10).build();
-
-        assertThat(etl.transform(old)).isEqualTo(expected);
+        Map<Integer, List<String>> old = new HashMap<Integer, List<String>>() {
+            {
+                put(1, Arrays.asList("A", "E", "I", "O", "U", "L", "N", "R", "S", "T"));
+                put(2, Arrays.asList("D", "G"));
+                put(3, Arrays.asList("B", "C", "M", "P"));
+                put(4, Arrays.asList("F", "H", "V", "W", "Y"));
+                put(5, Arrays.asList("K"));
+                put(8, Arrays.asList("J", "X"));
+                put(10, Arrays.asList("Q", "Z"));
+            }
+        };
+        old = Collections.unmodifiableMap(old);
+
+        Map<String, Integer> expected = new HashMap<String, Integer>() {
+            {
+                put("a", 1);
+                put("b", 3);
+                put("c", 3);
+                put("d", 2);
+                put("e", 1);
+                put("f", 4);
+                put("g", 2);
+                put("h", 4);
+                put("i", 1);
+                put("j", 8);
+                put("k", 5);
+                put("l", 1);
+                put("m", 3);
+                put("n", 1);
+                put("o", 1);
+                put("p", 3);
+                put("q", 10);
+                put("r", 1);
+                put("s", 1);
+                put("t", 1);
+                put("u", 1);
+                put("v", 4);
+                put("w", 4);
+                put("x", 8);
+                put("y", 4);
+                put("z", 10);
+            }
+        };
+        expected = Collections.unmodifiableMap(expected);
+
+        assertEquals(etl.transform(old), expected);
     }
 }