anchor.diff:  * Order the test output in some meaningful way, probably by depth in the
   dependency graph. (That way all skipped tests should be shown last.)
   * Update the defaults on this document to match the new default settings.
  +* Print test breakdown and totals before submission (similar to `test161
  +run`).
  +* Check user identity _before_ cloning and configuring the repository to
  +short-circuit when tokens change.
  +* Cache a copy of the cloned repository somewhere so that we can pull and
  +checkout rather than recloning every time (slow).
  +* Better error messages and hints about repository problems:
  +** Check and fail for dirty working trees
  +** Check and fail for unpushed refs
  +** Check and fail if it doesn't look like an OS/161 source tree, has
  +inappropriate files (`.o`), or is too large. (Prevent backend storage DOS
  +attacks.)
  +
  +=== Key saving
  +
  +Now that we are having students save a key through the web interface we need
  +to make sure that these keys get saved, associated with each successful
  +submission, and not destroyed even if they are changed later.
   
   === Environment inference
   
  
positive.code: ----
  
  At this point you are ready to start using GVM. We are currently building and
  testing `test161` with Go version `go1.6beta2`. However, because the Go
  compiler is now written in Go, installing versions of Go past 1.5 require
  install Go version 1.4 first.
  
  [source,bash]
  ----
  gvm install go1.4
  gvm use 1.4
  gvm install go1.6beta2
  gvm use 1.6beta2
  ----
  
  === `GOPATH`
  
negative.code: 
  [source,bash]
  ----
  go get -u github.com/ops-class/test161/test161
  ----
  
  == Configuration
  