Fix build on armv7-unknown-linux-gnueabihf

[misuzu]

Update Cargo.lock to allow building for armv7-unknown-linux-gnueabihf

With current Cargo.lock build fails:

% cross build --target armv7-unknown-linux-gnueabihf
   Compiling tokio-timer v0.2.0
   Compiling tokio-reactor v0.1.1
   Compiling tokio-threadpool v0.1.2
error[E0412]: cannot find type `Ordering` in this scope
  --> /cargo/registry/src/github.com-1ecc6299db9ec823/tokio-timer-0.2.0/src/atomic.rs:60:31
   |
60 |         pub fn load(&self, _: Ordering) -> u64 {
   |                               ^^^^^^^^ not found in this scope
help: possible candidates are found in other modules, you can import them into scope
   |
46 |     use std::cmp::Ordering;
   |
46 |     use std::sync::atomic::Ordering;
   |

error[E0412]: cannot find type `Ordering` in this scope
  --> /cargo/registry/src/github.com-1ecc6299db9ec823/tokio-timer-0.2.0/src/atomic.rs:64:42
   |
64 |         pub fn store(&self, val: u64, _: Ordering) {
   |                                          ^^^^^^^^ not found in this scope
help: possible candidates are found in other modules, you can import them into scope
   |
46 |     use std::cmp::Ordering;
   |
46 |     use std::sync::atomic::Ordering;
   |

error[E0412]: cannot find type `Ordering` in this scope
  --> /cargo/registry/src/github.com-1ecc6299db9ec823/tokio-timer-0.2.0/src/atomic.rs:68:45
   |
68 |         pub fn fetch_or(&self, val: u64, _: Ordering) -> u64 {
   |                                             ^^^^^^^^ not found in this scope
help: possible candidates are found in other modules, you can import them into scope
   |
46 |     use std::cmp::Ordering;
   |
46 |     use std::sync::atomic::Ordering;
   |

error[E0412]: cannot find type `Ordering` in this scope
  --> /cargo/registry/src/github.com-1ecc6299db9ec823/tokio-timer-0.2.0/src/atomic.rs:75:63
   |
75 |         pub fn compare_and_swap(&self, old: u64, new: u64, _: Ordering) -> u64 {
   |                                                               ^^^^^^^^ not found in this scope
help: possible candidates are found in other modules, you can import them into scope
   |
46 |     use std::cmp::Ordering;
   |
46 |     use std::sync::atomic::Ordering;
   |

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0412`.
error: Could not compile `tokio-timer`.
warning: build failed, waiting for other jobs to finish...
error: build failed

[kevincox]

Thanks. Can you please just acknowledge that you are releasing code under the project license: https://cla-assistant.io/kevincox/rustymedia?pullRequest=6

Other then that it looks good to merge.

[misuzu]

@kevincox done!

[kevincox]

Thanks.