Delete Cargo.lock from this repo

There's now a lock file upstream in rust-lang/rust so the one here isn't
actually used, and otherwise this crate is used as a dependency so the lock file
isn't respected anyway!

.gitignore

@@ -1,4 +1,5 @@
 /target
+Cargo.lock
 .cargo
 /config.stamp
 /Makefile
@@ -6,7 +7,6 @@
 src/doc/build
 src/etc/*.pyc
 src/registry/target
-src/registry/Cargo.lock
 rustc
 __pycache__
 .idea/

Cargo.toml

@@ -24,7 +24,7 @@ crypto-hash = "0.3"
 curl = "0.4.6"
 docopt = "0.8.1"
 env_logger = "0.4"
-error-chain = "0.11.0-rc.2"
+error-chain = "0.11.0"
 filetime = "0.1"
 flate2 = "0.2"
 fs2 = "0.4"