prevent gh-pages from deleting git-ignored dirs
add support for array type from jsonschema
upgrade readdirp
automatically normalize paths
add @_config property

At first I wanted to make deployers stateless, but that's getting to be
a huge pain because of how many things need to get passed around between
functions.
.gitignore doesn't need to be ignored

By ignoring it, we force all the files that are in there to not be
deployed, but we can't assume that... maybe make it an option later tho.

Also, since .gitignore files need to be committed, we'll get it back
when the deploy is over.
add ignore option for all deployers
make `getFileList()` paths relative to projectRoot