Add extractor stage that takes yaml/tsv list of files as input
Add pdf to text transform stage
Add docx to text transform stage
Merge branch 'master' of https://github.com/trec-kba/streamcorpus-pipeline
renaming extractor --> reader one more (trivial)
Wrap conversions in try/except
Revise input format following discussion with John/Steve
Merge pull request #1 from luac/master

New pipeline stages
Add root_path option
Merge pull request #3 from luac/master

Add root_path option
Pass creation time as unix timestamp instead of iso string
Coerce paths and target ids to str
Add a quick test for yaml files list reader
Add dependencies for pdf and docx conversions
allowing a writer to have an empty config block
tighter integration of kvlayer into streamcorpus_pipeline:
 * command line args now include kvlayer's default args
 * config files can now say:

     kvlayer: !include_func kvlayer.default_yaml

 * illustrated in  configs/john-smith-kvlayer.yaml
requiring new enough kvlayer
Merge pull request #4 from luac/master

Some bugfixes and a test case for the yaml reader
Add required dependencies
bumping version of kvlayer required to avoid postgres