Deprecate SortedMapSubject and SortedSetSubject.

#556

RELNOTES=Deprecated `SortedMapSubject` and `SortedSetSubject`. Users will have to perform assertions directly on the result of methods like `firstKey`. We haven't found sufficient demand for the classes to keep them.

core/src/main/java/com/google/common/truth/SortedMapSubject.java

@@ -36,9 +36,13 @@
 /**
  * Tests for {@link SortedMap} and {@link NavigableMap} objects. This class supports assertions
  * based on {@code NavigableMap}'s API even if the subject only implements {@code SortedMap}.
+ *
+ * @deprecated Perform assertions directly on the result of methods like {@code firstKey}. We
+ *     haven't found sufficient demand for this class to keep it.
  */
 // TODO(diamondm): identify use-cases for assertions on other NavigableMap methods, such as
 // ceilingKey(), and propose an API to support such assertions.
+@Deprecated
 public final class SortedMapSubject extends MapSubject {
   private final NavigableMap<?, ?> actualAsNavigableMap;
 

core/src/main/java/com/google/common/truth/SortedSetSubject.java

@@ -29,9 +29,13 @@
 /**
  * Tests for {@link SortedSet} and {@link NavigableSet} objects. This class supports assertions
  * based on {@code NavigableSet}'s API even if the subject only implements {@code SortedSet}.
+ *
+ * @deprecated Perform assertions directly on the result of methods like {@code first}. We haven't
+ *     found sufficient demand for this class to keep it.
  */
 // TODO(diamondm): identify use-cases for assertions on other NavigableSet methods, such as
 // ceiling(), and propose an API to support such assertions.
+@Deprecated
 public final class SortedSetSubject extends IterableSubject {
   private final NavigableSet<?> actualAsNavigableSet;