add customer table, dto, repository, service

src/main/kotlin/com/example/demo/providers/CustomerRepository.kt

@@ -0,0 +1,11 @@
+package com.example.demo.providers
+
+import com.example.demo.models.Customer
+import org.springframework.data.repository.CrudRepository
+import org.springframework.stereotype.Repository
+import java.util.*
+
+@Repository
+interface CustomerRepository: CrudRepository<Customer, Long> {
+    fun findByGuid(guid: UUID): Customer?
+}