Fix error 'BioCProjectPage' object has no attribute 'url'
Fix error 'BioCProjectPage' object has no attribute 'url'

Update bioconductor_skeleton to avoid error AttributeError: 'BioCProjectPage' object has no attribute 'url'
Example of package giving this error: bioconda-utils bioconductor-skeleton recipes config.yml FlowSorted.Blood.450k --pkg-version 1.16.0 --bioc-version 3.6

Traceback of the error:
Traceback (most recent call last):
  File "/home/murilo/miniconda3/bin/bioconda-utils", line 11, in <module>
    load_entry_point('bioconda-utils==0.12.2+84.gba7e0b9e.dirty', 'console_scripts', 'bioconda-utils')()
  File "/home/murilo/miniconda3/lib/python3.6/site-packages/bioconda_utils-0.12.2+84.gba7e0b9e.dirty-py3.6.egg/bioconda_utils/cli.py", line 606, in main
    argh.dispatch_commands([build, dag, dependent, lint, duplicates, bioconductor_skeleton, pypi_check, clean_cran_skeleton])
  File "/home/murilo/miniconda3/lib/python3.6/site-packages/argh/dispatching.py", line 328, in dispatch_commands
    dispatch(parser, *args, **kwargs)
  File "/home/murilo/miniconda3/lib/python3.6/site-packages/argh/dispatching.py", line 174, in dispatch
    for line in lines:
  File "/home/murilo/miniconda3/lib/python3.6/site-packages/argh/dispatching.py", line 277, in _execute_command
    for line in result:
  File "/home/murilo/miniconda3/lib/python3.6/site-packages/argh/dispatching.py", line 260, in _call
    result = function(*positional, **keywords)
  File "/home/murilo/miniconda3/lib/python3.6/site-packages/bioconda_utils-0.12.2+84.gba7e0b9e.dirty-py3.6.egg/bioconda_utils/cli.py", line 529, in bioconductor_skeleton
    skip_if_in_channels=skip_if_in_channels)
  File "/home/murilo/miniconda3/lib/python3.6/site-packages/bioconda_utils-0.12.2+84.gba7e0b9e.dirty-py3.6.egg/bioconda_utils/bioconductor_skeleton.py", line 916, in write_recipe
    fout.write(open(proj.meta_yaml).read())
  File "/home/murilo/miniconda3/lib/python3.6/site-packages/bioconda_utils-0.12.2+84.gba7e0b9e.dirty-py3.6.egg/bioconda_utils/bioconductor_skeleton.py", line 737, in meta_yaml
    ('home', sub_placeholders(self.url)),
AttributeError: 'BioCProjectPage' object has no attribute 'url'
bioconda/bioconda-utils,bioconda/bioconda-utils,bioconda/bioconda-utils