fixes for wrong build. entities always extends BaseEntity, tables must contains version column

src/main/java/ru/ulstu/conference/model/Conference.java

@@ -1,9 +1,11 @@
 package ru.ulstu.conference.model;
 
+import ru.ulstu.core.model.BaseEntity;
+
 import javax.persistence.Entity;
 import javax.persistence.Table;
 
 @Entity
 @Table(name = "conference")
-public class Conference {
+public class Conference extends BaseEntity {
 }

src/main/resources/db/changelog-20190331_000010-schema.xml

@@ -54,4 +54,10 @@
                                  constraintName=" fk_deadlines_conference" referencedTableName="conference"
                                  referencedColumnNames="id"/>
     </changeSet>
+
+    <changeSet author="orion" id="20190331_000010-5">
+        <addColumn tableName="conference">
+            <column name="version" type="integer"/>
+        </addColumn>
+    </changeSet>
 </databaseChangeLog>