
A named env cannot contain `.` and `/`. So when a user runs `spack env create ./here` do not error but treat it as `spack env create -d ./here`. Also fix help string of `spack env create`, which seems to have been copied from `activate` incorrectly.
A named env cannot contain `.` and `/`. So when a user runs `spack env create ./here` do not error but treat it as `spack env create -d ./here`. Also fix help string of `spack env create`, which seems to have been copied from `activate` incorrectly.