Vendor sedlex and ppx_tools_versioned #6
Description
These two dependencies are very difficult to get right when mixed with other package constraints. Flow depends on a very specific version of ppx_tools_versioned, and an old sedlex. If you bump the ppx_tools_versioned from 5.2 to 5.2.1 or 5.2.2, then sedlex 1.99.4 automatically get promoted to 2.0 since sedlex 2.0 is the only one that can work with ppx_tools_versioned > 5.2. Then flow_parser will fail to build. This makes it very hard to work with the master branch of jsoo. A project will fail to build when mixed with flow_parser and jsoo master which is really unfortunate since the two projects would be useful together.
vendoring sedlex and ppx_tools_versioned seems like the easiest fix.