Simplify recipe parsing and environment creation

Closes #70

See merge request !237

[build] Simplify recipe parsing and environment creation significantly and fixes multiple environment creation issues; Closes #70

[build] Simplify recipe parsing and environment creation significantly and fixes multiple environment creation issues; Closes #70

Remove libgfortran4 from list of packages to be installed (current linux install issues)

See merge request !236

Fix readme updates

Closes #78

See merge request !235

Add a custom BOBRC file

See merge request !234

to customize the location of automated downloads
This should prevents errors like https://gitlab.idiap.ch/bob/bob.bio.face/-/jobs/238053

Revert "Merge branch 'revert-a1a488bb' into 'master'"

See merge request !233

This reverts merge request !232

Revert "Merge branch 'revert-51677b07' into 'master'"

See merge request !232

This reverts merge request !228

[bootstrap] Use http instead of https (faster and easier to maintain)

See merge request !231

Bump pybind11 version to 2.6.2, following bob.devel

See merge request !230

[proxy] Use proxy for other channels, i.e., conda-forge, too

See merge request !224

Add conda-forge as a low priority channel in the builds

See merge request !229

Revert "Merge branch 'bob-devel-update' into 'master'"

See merge request !228