chore: remove unused imports (#794)

Author: Zichen1028

lib/src/main/java/com/auth0/jwt/impl/PayloadDeserializer.java

@@ -9,7 +9,6 @@
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.DeserializationContext;
 import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectReader;
 import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
 
 import java.io.IOException;

lib/src/test/java/com/auth0/jwt/JWTTest.java

@@ -12,7 +12,6 @@
 import java.security.interfaces.ECKey;
 import java.security.interfaces.RSAKey;
 import java.time.Clock;
-import java.time.Duration;
 import java.time.Instant;
 import java.time.ZoneId;
 import java.util.Base64;

lib/src/test/java/com/auth0/jwt/impl/PayloadDeserializerTest.java

@@ -11,7 +11,6 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.*;
 import org.hamcrest.collection.IsCollectionWithSize;
-import org.hamcrest.collection.IsEmptyCollection;
 import org.hamcrest.core.IsIterableContaining;
 import org.junit.Before;
 import org.junit.Rule;

lib/src/test/java/com/auth0/jwt/impl/PayloadImplTest.java

@@ -3,7 +3,6 @@
 import com.auth0.jwt.interfaces.Claim;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.ObjectReader;
 import com.fasterxml.jackson.databind.node.TextNode;
 import org.hamcrest.collection.IsCollectionWithSize;
 import org.hamcrest.core.IsIterableContaining;

lib/src/test/java/com/auth0/jwt/interfaces/VerificationTest.java

@@ -12,7 +12,6 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.hasEntry;
 import static org.hamcrest.Matchers.instanceOf;
-import static org.junit.Assert.assertThrows;
 
 /**
  * Tests for any default method implementations in the {@link Verification} interface.