v0.8.6

Added support for Spring to inject Trading Strategies. Some dependency updates too.

• #84 - support for Spring injection of Trading Strategies. Thanks to @kuceraf for this. The legacy mechanism for injecting strategies by class name is still supported.
• Updated to Spring Boot 1.5.10.RELEASE
• Updated spring-tx to 4.3.14.RELEASE
• Updated Google Guava to 24.0-jre
• Updated to Gradle 4.5