CWL parser fails for numeric characters in cwl name

The conduit build command fails to properly parse cwl containing numerical variable names
example
is3D: int?
produces the following error related to the creation of datajoint variables

File "/conduit/utils/cwlparser.py", line 81, in __init__
self.job_param_db = schema(create_dj_schema(self.cwl['inputs'], self.workflow_name))()
File "/usr/local/lib/python3.6/site-packages/datajoint/schema.py", line 208, in __call__
self.process_relation_class(cls, context=dict(context, self=cls, **{cls.__name__: cls}))
File "/usr/local/lib/python3.6/site-packages/datajoint/schema.py", line 186, in process_relation_class
instance.declare(context)
File "/usr/local/lib/python3.6/site-packages/datajoint/table.py", line 62, in declare
sql, uses_external = declare(self.full_table_name, self.definition, context)
File "/usr/local/lib/python3.6/site-packages/datajoint/declare.py", line 223, in declare
name, sql, is_external = compile_attribute(line, in_key, foreign_key_sql)
File "/usr/local/lib/python3.6/site-packages/datajoint/declare.py", line 260, in compile_attribute
line=err.args[0], pos=err.args[1], msg=err.args[2]))
datajoint.errors.DataJointError: Declaration error in position 3 in line: