Minor cleanup removing unnecessary imports and suppress warnings (#92)

Author: kinow

oauth2_http/java/com/google/auth/oauth2/DefaultCredentialsProvider.java

@@ -38,12 +38,10 @@
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
-import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.security.AccessControlException;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.Locale;
 

oauth2_http/java/com/google/auth/oauth2/GoogleCredentials.java

@@ -183,7 +183,6 @@ public boolean createScopedRequired() {
    * If the credentials support scopes, create a copy of the the idenitity with the specified
    * scopes, otherwise returns the same instance.
    */
-  @SuppressWarnings("unused")
   public GoogleCredentials createScoped(Collection<String> scopes) {
     return this;
   }

oauth2_http/javatests/com/google/auth/oauth2/DefaultCredentialsProviderTest.java

@@ -408,7 +408,6 @@ private void testUserProvidesToken(TestDefaultCredentialsProvider testProvider,
   public static class MockAppEngineCredentials extends GoogleCredentials {
     private static final long serialVersionUID = 2695173591854484322L;
 
-    @SuppressWarnings("unused")
     public MockAppEngineCredentials(Collection<String> scopes) {
     }