nmodl: testing variant to unbreak the tests

[heerener]

#2440 breaks the nmodl tests because they use pytest. Let's add a variant so we can install those optional dependencies when testing.

[bbpbuildbot]

Thank you for your pull request!

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[matz-e]

I'd bring this in line with NEURON:

var/spack/repos/builtin/packages/neuron/package.py
34:    variant("tests", default=False, description="Enable building tests")

[matz-e]

One last nitpick (I promise): line 100 build_testing should then be define_from_variant, too :)

[bbpbuildbot]

To test your PR, use the following on BlueBrain5:

unset MODULEPATH
. /gpfs/bbp.cscs.ch/ssd/apps/bsd/pulls/2441/config/modules.sh
module load unstable

Please test the following updated modules:

• neurodamus-hippocampus/2.1.0
• neurodamus-mousify/1.6-3.2.1-2.8.1
• neurodamus-neocortex-plasticity/2.1.0
• neurodamus-neocortex/2.1.0
• neurodamus-thalamus/2.1.0
• neuron/9.0.a16
• psp-validation/0.5.0
• py-bbp-workflow/3.1.57
• py-bluepyemodel/0.0.105
• py-bluepyemodelnexus/0.0.8
• py-bluepymm/0.8.7
• py-bluepyopt/1.14.11
• py-minis-validation/0.0.5
• py-morph-tool/2.9.1
• py-region-grower/1.2.9
• py-synthesis-workflow/1.1.0
• py-visual-cortex-analysis/0.2.3

[bbpbuildbot]

To test your PR, use the following on BlueBrain5:

unset MODULEPATH
. /gpfs/bbp.cscs.ch/ssd/apps/bsd/pulls/2441/config/modules.sh
module load unstable

Please test the following updated modules:

• neurodamus-hippocampus/2.1.0
• neurodamus-mousify/1.6-3.2.1-2.8.1
• neurodamus-neocortex-plasticity/2.1.0
• neurodamus-neocortex/2.1.0
• neurodamus-thalamus/2.1.0
• neuron/9.0.a16
• psp-validation/0.5.0
• py-bbp-workflow/3.1.57
• py-bluepyemodel/0.0.105
• py-bluepyemodelnexus/0.0.8
• py-bluepymm/0.8.7
• py-bluepyopt/1.14.11
• py-minis-validation/0.0.5
• py-morph-tool/2.9.1
• py-region-grower/1.2.9
• py-synthesis-workflow/1.1.0
• py-visual-cortex-analysis/0.2.3

[bbpbuildbot]

The following build jobs of the deployment for this PR failed:

• applications / hpc
• applications / libraries
• applications / nexus
• applications / nse
• applications / science

Please fix the following packages that failed to build:

• nmodl (6cjxlma35r53eqyittwl2mtsuyha6ki2)
• nmodl (bdjb6daqk4blauhlrjgm6lkcia2ngkh2)
• nmodl (i4vqfuvh6lncqwihi2awt7lemyh47hq4)
• nmodl (mhv7u5dcdm56jaeiisgrf2jpgw755bqt)
• nmodl (umucype7tfl352hquexq422427lezbuh)
• nmodl (ysnvx2hkazb7xmrmiqq7dgr57xhoaxdp)

[bbpbuildbot]

The following build jobs of the deployment for this PR failed:

• applications / hpc
• applications / libraries
• applications / nexus
• applications / nse
• applications / science

Please fix the following packages that failed to build:

• nmodl (6cjxlma35r53eqyittwl2mtsuyha6ki2)
• nmodl (bdjb6daqk4blauhlrjgm6lkcia2ngkh2)
• nmodl (i4vqfuvh6lncqwihi2awt7lemyh47hq4)
• nmodl (umucype7tfl352hquexq422427lezbuh)
• nmodl (ysnvx2hkazb7xmrmiqq7dgr57xhoaxdp)

[bbpbuildbot]

To test your PR, use the following on BlueBrain5:

unset MODULEPATH
. /gpfs/bbp.cscs.ch/ssd/apps/bsd/pulls/2441/config/modules.sh
module load unstable

Please test the following updated modules:

• neurodamus-hippocampus/2.1.0
• neurodamus-mousify/1.6-3.2.1-2.8.1
• neurodamus-neocortex-plasticity/2.1.0
• neurodamus-neocortex/2.1.0
• neurodamus-thalamus/2.1.0
• neuron/9.0.a16
• psp-validation/0.5.0
• py-bbp-workflow/3.1.57
• py-bluepyemodel/0.0.105
• py-bluepyemodelnexus/0.0.8
• py-bluepymm/0.8.7
• py-bluepyopt/1.14.11
• py-minis-validation/0.0.5
• py-morph-tool/2.9.1
• py-region-grower/1.2.9
• py-synthesis-workflow/1.1.0
• py-visual-cortex-analysis/0.2.3

[bbpbuildbot]

To test your PR, use the following on BlueBrain5:

unset MODULEPATH
. /gpfs/bbp.cscs.ch/ssd/apps/bsd/pulls/2441/config/modules.sh
module load unstable

Please test the following updated modules:

• neurodamus-hippocampus/2.1.0
• neurodamus-mousify/1.6-3.2.1-2.8.1
• neurodamus-neocortex-plasticity/2.1.0
• neurodamus-neocortex/2.1.0
• neurodamus-thalamus/2.1.0
• neuron/9.0.a16
• psp-validation/0.5.0
• py-bbp-workflow/3.1.57
• py-bluepyemodel/0.0.105
• py-bluepyemodelnexus/0.0.8
• py-bluepymm/0.8.7
• py-bluepyopt/1.14.11
• py-minis-validation/0.0.5
• py-morph-tool/2.9.1
• py-region-grower/1.2.9
• py-synthesis-workflow/1.1.0
• py-visual-cortex-analysis/0.2.3