gnu: Remove rust-num-cpus-1.10.

gnu: Remove rust-num-cpus-1.10.

* gnu/packages/rust-apps.scm (ripgrep)[arguments]: Replace rust-num-cpus-1.10 with 1.11.
* gnu/packages/crates-io.scm
  (rust-crossbeam-channel-0.4, rust-crossbeam-channel-0.3,
  rust-futures-executor-preview-0.3, rust-hyper-0.12,
  rust-jobserver-0.1, rust-tokio-0.2)[arguments]: Likewise.
  (rust-gimli-0.18, rust-tokio-core-0.1,
  rust-tokio-io-pool-0.1, rust-tokio-reactor-0.1)[arguments]: Likewise; don't skip build.
  (rust-tokio-0.1): Don't skip build. Replace rust-num-cpus-1.10 with 1.11,
  rust-env-logger-0.6 with 0.5.
  (rust-tokio-threadpool-0.1)[arguments]: Don't skip build. Replace
  rust-num-cpus-1.10 with 1.11, rust-rand-0.4 with 0.6,
  rust-env-logger-0.6 with 0.5. Add rust-lazy-static-1.
  (rust-num-cpus-1.10): Remove variable.