message: add newline to `cargo install .` error message for easier reading.
diff: @@ -69,7 +69,7 @@ impl<'cfg, 'a> InstallablePackage<'cfg, 'a> {
  if name == "." {
  bail!(
  "To install the binaries for the package in current working \
  - directory use `cargo install --path .`. \
  + directory use `cargo install --path .`. \n\
  Use `cargo build` if you want to simply build the package."
  )
  }
  