From [https://github.com/appc/spec/blob/master/spec/aci.md](https://github.com/appc/spec/blob/master/spec/aci.md):
>environment (list of objects, optional) represents the app's environment variables (ACE can append). The listed objects must have two key-value pairs: name and value. The name must consist solely of letters, digits, and underscores '_' as outlined in IEEE Std 1003.1-2008, 2016 Edition, with practical considerations dictating that the name may also include periods '.' and hyphens '-'. The value is an arbitrary string. These values are not evaluated in any way, and no substitutions are made.
Dotted environment variables are frequently used as a part of the Spring Boot pattern. (re: ZD-6116)
This PR specifically doesn't address the conversion of hyphens (`-`) due to an issue with rkt [[Nomad GH # 2358]](https://github.com/hashicorp/nomad/issues/2358).
