Fix https://github.com/spring-projects/sts4/issues/66

Add  'tags' property in 'resource' type in concourse
editor schema.

headless-services/concourse-language-server/src/main/java/org/springframework/ide/vscode/concourse/PipelineYmlSchema.java

@@ -230,6 +230,7 @@ public class PipelineYmlSchema implements YamlSchema {
 		addProp(t_resource, "type", t_resource_type_name).isRequired(true);
 		addProp(t_resource, "source", resourceSource);
 		addProp(t_resource, "check_every", t_duration);
+		addProp(t_resource, "tags", t_strings);
 		addProp(t_resource, "webhook_token", t_ne_string);
 
 		AbstractType t_image_resource = f.ybean("ImageResource");

headless-services/concourse-language-server/src/main/resources/desc/Resource/tags.md

@@ -0,0 +1,3 @@
+*Optional*. A list of tags to determine which workers the checks will be performed on. You'll want to specify this if 
+the source is internal to a worker's network, for example. See also [tags](https://concourse-ci.org/tags-step-modifier.html) step modifier.
+

headless-services/concourse-language-server/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java

@@ -272,6 +272,21 @@ public class ConcourseEditorTest {
 		);
 	}
 
+	@Test
+	public void resource_tags() throws Exception {
+		Editor editor = harness.newEditor(
+				"resources:\n" +
+				"- name: abc\n" +
+				"  type: git\n" +
+				"  tags:\n"+
+				"  - sometag\n" +
+				"  - othertag\n"
+		);
+		editor.assertProblems("abc|Unused");
+
+		editor.assertHoverContains("tags", "determine which workers");
+	}
+
 	@Test
 	public void primaryStepCompletions() throws Exception {
 		assertContextualCompletions(
@@ -3336,6 +3351,7 @@ public class ConcourseEditorTest {
 		editor.assertCompletionLabels(
 				//For the 'exact' context:
 				"check_every",
+				"tags",
 				"webhook_token",
 				//"name", exists
 				//"source", exists