Explicitly use MySQL mode for H2 database

Signed-off-by: Pekka Helenius <fincer89@hotmail.com>

bookstore/src/main/resources/application-dev.properties

@@ -7,7 +7,10 @@
 # Temporary, volatile database
 spring.h2.console.enabled = true
 spring.h2.console.path    = /h2-console
-spring.datasource.url     = jdbc:h2:mem:testdb
+
+# Ref: http://h2database.com/html/features.html
+#
+spring.datasource.url     = jdbc:h2:mem:testdb;MODE=MySQL
 spring.jpa.show-sql       = true