expose external id in shop

Author: ajungg

build.gradle

@@ -24,7 +24,7 @@ allprojects {
     }
 
     project.ext {
-        sdkVersion='0.8.19'
+        sdkVersion='0.8.20'
         versionCode=1
 
         compileSdkVersion=28

core/src/main/java/io/snabble/sdk/Shop.java

@@ -51,6 +51,7 @@ public String getDayOfWeek() {
     }
 
     private String id;
+    private String externalId;
     private String name;
     private Service[] services;
     private String street;
@@ -72,6 +73,10 @@ public String getId() {
         return id;
     }
 
+    public String getExternalId() {
+        return externalId;
+    }
+
     public Service[] getServices() {
         return services;
     }
@@ -138,6 +143,7 @@ static Shop[] fromJson(String json) {
 
     public static class Builder {
         private String id;
+        private String externalId;
         private String name;
         private Shop.Service[] services;
         private String street;
@@ -207,6 +213,11 @@ public Builder openingHours(OpeningHourSpecification[] openingHours) {
             return this;
         }
 
+        public Builder externalId(String externalId) {
+            this.externalId = externalId;
+            return this;
+        }
+
         public Builder external(JsonElement external) {
             this.external = external;
             return this;
@@ -216,6 +227,7 @@ public Shop create() {
             Shop shop = new Shop();
 
             shop.id = id;
+            shop.externalId = externalId;
             shop.name = name;
             shop.services = services;
             shop.street = street;