Support for running static content apps on Apache HTTP Server

One thing to think supporting in this buildpack is the ability for users to use Apache HTTP Server to serve static content apps. 

Provided the app has a buildpack.yml with the structure below, users would run `pack build --buildpack paketo-buildpacks/httpd --buildpack paketo-buildpacks/staticfile`.
Buildpack.yml
```
staticfile:
  httpd:
    root: "public"
     ...... # other keys
```