Release 0.2.12

This is release 0.2.12 of ncbi-genome-download.

Highlights of this release are:

• Parallel downloads of checksum files (Thanks to Adelme Bazin (@axbazin))
• New --flat-output option to dump all downloaded files into a single directory
• We now have a Chinese translation of the README (Thanks James Yang (@jamesyangget))

Detailed changes:

Adelme Bazin (5):
      core : Checking MD5SUM in parallel when more than one process is allowed
      add integration test to check if metadata table was filled properly. Expected failure when using multiprocessing.
      fill metadata table in config_download instead of download_file_job to avoid problems with multiprocessing
      modify the metadata_fill test functions so that they follow the same logic than the current code
      fix the call to Pool with the 'with' statement for python2

Kai Blin (13):
      core: Allow keeping the downloaded files in a flat hierarchy
      chore: Break long help text lines
      core: Fix the --flat-output description
      README: Update install documentation
      core: Add tests for type material downloads
      chore: Add docstring and coverage skip to `downloadjob_creator_caller`
      config: Test `is_compatible_assembly_accession()` in fuzzy_accession mode
      core: Add a docstring to new fill_metadata function
      core: Acquire the metadata table object outside of the download loops
      config: Also support downloading metagenomes
      core: Check for exact match on genus name before trying to capitalise it
      chore: Update README to note that 0.2.12 is the last version to support Python 2
      Bump version number to 0.2.12

James Yang (1):
      translate README.md into Chinese (#97)