freeze SpiceEV version in requirements

[PaulScheerRLI]

Right now the defined version of SpiceEV is "latest". This leads to the following problems.
SpiceEV changes can lead to SimBA not working
SimBA simulation results may not be easily reproduceable
The SpiceEV version is not tracked in the resulting output/log/input copy

[j-brendel]

Do you think it would be enough to have that defined in the releases? This is the current approach and "dev" is meant as a developers branch.
Still it would be nice to have "The SpiceEV version [] tracked in the resulting output/log/input copy" but afaik there was no technical solution for this problem.