Replaced increment table with sequnce for sqlserver

resolves #781

Author: cppwfs

spring-cloud-task-core/src/main/resources/org/springframework/cloud/task/schema-sqlserver.sql

@@ -25,7 +25,7 @@ CREATE TABLE TASK_TASK_BATCH (
 	references TASK_EXECUTION(TASK_EXECUTION_ID)
 ) ;
 
-CREATE TABLE TASK_SEQ (ID BIGINT IDENTITY);
+CREATE SEQUENCE TASK_SEQ START WITH 0 MINVALUE 0 MAXVALUE 9223372036854775807 NO CACHE NO CYCLE;
 
 CREATE TABLE TASK_LOCK  (
   LOCK_KEY CHAR(36) NOT NULL,