Running tests in the leiningen process subverts dependencies

[gfredericks]

The :eval-in :leiningen change introduced by https://github.com/slagyr/speclj/pull/67 is subtly dangerous as a default setting.

In particular:

• the version of clojure being used will be set to whatever leiningen happens to use, regardless of what the user wants for their own project
• the versions of other dependencies can change if any plugins depend on different versions of those dependencies, and this will not be reported by tasks like lein deps :tree.

This second issue has already resulted in hours of spooky debugging at work (and the details of the libraries involved are reproduced in this skeleton project).

As Phil noted in a comment on the original PR, it takes one line for a user to opt-in to this feature if they want it.

[slagyr]

Thanks for the report. This has been resolved in 3.0.0. The speclj lein task will now set :eval-in to :subprocess and overriding it can be done with :speclj-eval-in :leiningen.