support current AWS environments

[dareno]

Problem Description

This plugin is hard-coded to an environment that no longer exists. The deploy command will fail with the following message:

com.amazonaws.AmazonServiceException: No Solution Stack named '32bit Amazon Linux running Tomcat 7' found.

Root Cause

Hard-coded environment selection:

lein-beanstalk/src/leiningen/beanstalk/aws.clj

Line 166 in d141892

"32bit Amazon Linux running Tomcat 7")))))

Currently supported "Java with Tomcat" environments: https://docs.aws.amazon.com/elasticbeanstalk/latest/platforms/platforms-supported.html#platforms-supported.java

Versions:

• lein: Leiningen 2.8.1 on Java 1.8.0_161 Java HotSpot(TM) 64-Bit Server VM
• plugin: :plugins [[lein-beanstalk "0.2.7"]]

[weavejester]

I don't think I have time to work on Lein-Beanstalk anymore, so feel free to fork it.