Change tei to solr general script to use slug params

[jduss4]

https://github.com/CDRH/data/blob/master/scripts/xslt/cdrh_to_solr/solr_transform_tei.xsl#L19

Rather than finding the slug from the project path, we could use the slug parameter that is already being passed into the xslt:
https://github.com/CDRH/data/blob/master/config/config.example.yml#L37

I'm having trouble getting neihardt's uris to come out correctly in solr and I discovered this, though I'm not sure that it is currently contributing to my neihardt problem.

[jduss4]

:(

        "id":"nei.j4c.1.12-14",
        "slug":"",
        "project":"neihardt",
        "uri":"http://rosie.unl.edu/transmississippi/files/nei.j4c.1.12-14.html",
        "uriXML":"http://rosie.unl.edu/data/projects/neihardt//tei/nei.j4c.1.12-14.xml",
        "uriHTML":"http://rosie.unl.edu/data/projects/neihardt//html-generated/nei.j4c.1.12-14.txt",

[jduss4]

Now using the passed in parameter for slug