Bump up KC version to 1.6.0 (#344)

* Bump up KC version to 1.6.0

Change logs:

[FEATURES]
1. JMX features(Metrics)

[BUGFIXES]
1. Regionless url regex support
2. Vulnerable Jersey transitive dependency through
   schema-registry-client
3. Do not update committed offset(In memory) and eventually to Kafka if
   insertFiles has failed. (Edge cases when we miss offsets for
   ingestion when Snowpipe REST API has failed or when account is locked
   for few mins)

* Fix VULN CVE-2021-38153 which was suggested in whitesource script

* Fixing kafka-schema-registry-client in pom confluent(fixed in maven version)

pom.xml

@@ -12,7 +12,7 @@
 
     <groupId>com.snowflake</groupId>
     <artifactId>snowflake-kafka-connector</artifactId>
-    <version>1.5.5</version>
+    <version>1.6.0</version>
     <packaging>jar</packaging>
     <name>Snowflake Kafka Connector</name>
     <description>Snowflake Kafka Connect Sink Connector</description>
@@ -242,6 +242,9 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
                 <version>2.9.1</version>
+                <configuration>
+                    <detectJavaApiLink>false</detectJavaApiLink>
+                </configuration>
                 <executions>
                     <execution>
                         <id>attach-javadocs</id>
@@ -287,7 +290,7 @@
         <dependency>
             <groupId>org.apache.kafka</groupId>
             <artifactId>connect-api</artifactId>
-            <version>2.7.0</version>
+            <version>2.8.1</version>
             <scope>provided</scope>
             <exclusions>
                 <exclusion>

pom_confluent.xml

@@ -13,7 +13,7 @@
 
     <groupId>com.snowflake</groupId>
     <artifactId>snowflake-kafka-connector</artifactId>
-    <version>1.5.5</version>
+    <version>1.6.0</version>
     <packaging>jar</packaging>
     <name>Snowflake Kafka Connector</name>
     <description>Snowflake Kafka Connect Sink Connector</description>
@@ -337,7 +337,7 @@
         <dependency>
             <groupId>org.apache.kafka</groupId>
             <artifactId>connect-api</artifactId>
-            <version>2.7.0</version>
+            <version>2.8.1</version>
             <scope>provided</scope>
             <exclusions>
                 <exclusion>
@@ -406,7 +406,7 @@
         <dependency>
             <groupId>io.confluent</groupId>
             <artifactId>kafka-schema-registry-client</artifactId>
-            <version>5.5.1</version>
+            <version>6.2.0</version>
             <exclusions>
                 <exclusion>
                     <groupId>io.confluent</groupId>

src/main/java/com/snowflake/kafka/connector/Utils.java

@@ -46,7 +46,7 @@
 public class Utils {
 
   // Connector version, change every release
-  public static final String VERSION = "1.5.5";
+  public static final String VERSION = "1.6.0";
 
   // connector parameter list
   public static final String NAME = "name";