fix remove unique constraint for collection_series.

Fix php-coder#986

Author: mukeshk

src/main/resources/liquibase/version/0.4.1.xml

@@ -8,5 +8,6 @@
 	<include file="0.4.1/2019-07-21--series_sales_transaction_url_length.xml" relativeToChangelogFile="true"/>
 	<include file="0.4.1/2019-08-06--test_user_with_series_in_collection.xml" relativeToChangelogFile="true"/>
 	<include file="0.4.1/2019-08-31--test_similar_series.xml" relativeToChangelogFile="true"/>
+	<include file="0.4.1/2019-09-18--rollback_collection_unique_series_constraint.xml" relativeToChangelogFile="true"/>
 
 </databaseChangeLog>

src/main/resources/liquibase/version/0.4.1/2019-09-18--rollback_collection_unique_series_constraint.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<databaseChangeLog
+	xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
+		http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.0.xsd">
+		
+	<changeSet author="mukeshk" id="drop-unique-constraint-from-collections_series-table">
+		<comment>Remove unique constraint (collection_id,series_id) from collection_series</comment>
+			<dropUniqueConstraint
+				constraintName="uc_collections_series_collection_id_series_id"
+				tableName="collections_series"/>	
+	</changeSet>
+
+</databaseChangeLog>