Update to Spring Boot 1.5

[kazuki43zoo]

Update to the Spring Boot 1.5

[kazuki43zoo]

The build is successful on Travis CI using Spring Boot 1.5.0.RC1.
See https://travis-ci.org/kazuki43zoo/mybatis-spring-boot/builds/189724545.

[kazuki43zoo]

The build is successful on Travis CI using Spring Boot 1.5.1.RELEASE.
See https://travis-ci.org/kazuki43zoo/mybatis-spring-boot/builds/198104373.

[kazuki43zoo]

The build is successful on Travis CI using Spring Boot 1.5.2.RELEASE.
See https://travis-ci.org/kazuki43zoo/mybatis-spring-boot/builds/207443918.

[eddumelendez]

@kazuki43zoo I would like to release 1.2.1 this week with the addition to MybatisTest annotation, then upgrade to 1.3.0 to be fully compatible with spring boot 1.5.x. WDYT?

[kazuki43zoo]

@eddumelendez My oponion is same with you !!

[kazuki43zoo]

I've added new milestone(1.3.0) and included this.