Build-dependencies cannot use the Name: version syntax [yeb]

[riccardomurri]

This abridged syntax is accepted by dependencies: in .yeb files::

    dependencies:
      - Autoconf: 2.69

However, the same syntax is not accepted in the builddependencies
(and possibly other) sections; EB errors out:

    ERROR: Failed to process easyconfig /net/nfs4/nfs.hydra/home/rmurri/givaro.yeb: Dependency specified without name: {'external_module_metadata': {}, 'full_mod_name': None, 'build_only': True, 'versionsuffix': '', 'external_module': False, 'dummy': False, 'Autoconf': 2.69, 'toolchain': {'version': '2015a', 'name': 'foss'}, 'name': None, 'short_mod_name': None, 'version': None, 'hidden': False}

[boegel]

fixed in #1818, thanks for reporting this @riccardomurri!