currently can't publish on `conda-forge`, due to `cql2` dependency

[Scartography]

• issue comes from this import and the usage in query parsing:

  mapchete-eo/mapchete_eo/search/base.py

  Line 7 in d389f8a

  from cql2 import Expr

• "twin" issue created at the cql2 repository: publish cql2 package on conda-forge as anaconda package developmentseed/cql2-rs#128