test fix for expandedEnv - straight `to.equal` assertion was failing since
honk-cake uses its own exec.bin function to run the tests, by default already
adding the ./lib path twice, failing like:

1) Exec expandedEnv should add expand and resolve paths in the node path:

      actual

      "/Users/nat/src/honk-cake/lib:/Users/nat/src/honk-cake/lib"

      expected

      "/Users/nat/src/honk-cake/lib"

* changed the input for the function in the test to use './honk' as the input for
the path to expand and changed the test to use to.have.string instead of equals
since it's appending to the current path

* separated tests for calling with and without an environment to expand into
different contexts
Merge pull request #2 from natlownes/test_fix_expanded_env

test fix for expandedEnv - straight `to.equal` assertion was failing