Merge branch '331-reduce-number-of-connections-in-the-pool' into 'master'

Resolve "reduce number of connections in the pool"

Closes #331

See merge request piotr.gawron/minerva!219

persist/src/main/resources/dataSource.xml

@@ -17,7 +17,7 @@
 		<property name="jdbcUrl" value="${database.uri}" />
 		<property name="user" value="${database.username}" />
 		<property name="password" value="${database.password}" /> 
-		<property name="maxPoolSize" value="100" />
+		<property name="maxPoolSize" value="90" />
 		<property name="maxStatements" value="5" />
 		<property name="minPoolSize" value="5" />
 	 </bean>