Change postalCode to String

Author: whoisxmlapi

README.md

@@ -18,7 +18,7 @@ The java library for the [Whois XML API service](https://whois.whoisxmlapi.com/)
 ```
 ```groovy
     dependencies {
-        implementation 'com.whoisxmlapi:whois-api-java:v1.0.4'
+        implementation 'com.whoisxmlapi:whois-api-java:v1.1.0'
     }
 ```
 
@@ -36,7 +36,7 @@ The java library for the [Whois XML API service](https://whois.whoisxmlapi.com/)
 	<dependency>
 	    <groupId>com.whoisxmlapi</groupId>
 	    <artifactId>whois-api-java</artifactId>
-	    <version>v1.0.4</version>
+	    <version>v1.1.0</version>
 	</dependency>
 ```
 ### Jar files

build.gradle

@@ -7,7 +7,7 @@ sourceCompatibility = 1.8
 targetCompatibility = 1.8
 
 group 'com.whoisxmlapi'
-version '1.0.4'
+version '1.1.0'
 
 repositories {
     mavenCentral()
@@ -38,7 +38,7 @@ publishing {
         mavenJava(MavenPublication) {
             artifactId = 'whois-api-client'
             groupId = 'com.whoisxmlapi'
-            version = '1.0.4'
+            version = '1.1.0'
             from components.java
             pom {
                 name = 'WhoisXML API client'

src/main/java/com/whoisxmlapi/whoisapi/model/BaseContact.java

@@ -11,7 +11,7 @@ public abstract class BaseContact {
     protected String street2;
     protected String city;
     protected String state;
-    protected Integer postalCode;
+    protected String postalCode;
     protected String country;
     protected String email;
     protected String telephone;
@@ -41,8 +41,8 @@ public Optional<String> getState() {
         return OptionalBuilder.buildOptionalString(this.state);
     }
 
-    public Optional<Integer> getPostCode() {
-        return OptionalBuilder.buildOptionalInt(this.postalCode);
+    public Optional<String> getPostCode() {
+        return OptionalBuilder.buildOptionalString(this.postalCode);
     }
 
     public Optional<String> getCountry() {