Upgrade dependencies (#2513)

## Proposed Changes

* Consolidate Tokio versions: everything now uses the latest v1.10.0, no more `tokio-compat`.
* Many semver-compatible changes via `cargo update`. Notably this upgrades from the yanked v0.8.0 version of crossbeam-deque which is present in v1.5.0-rc.0
* Many semver incompatible upgrades via `cargo upgrades` and `cargo upgrade --workspace pkg_name`. Notable ommissions:
    - Prometheus, to be handled separately: https://github.com/sigp/lighthouse/issues/2485
    - `rand`, `rand_xorshift`: the libsecp256k1 package requires 0.7.x, so we'll stick with that for now
    - `ethereum-types` is pinned at 0.11.0 because that's what `web3` is using and it seems nice to have just a single version
    
## Additional Info

We still have two versions of `libp2p-core` due to `discv5` depending on the v0.29.0 release rather than `master`. AFAIK it should be OK to release in this state (cc @AgeManning )

slasher/Cargo.toml

@@ -16,7 +16,7 @@ filesystem = { path = "../common/filesystem" }
 lmdb = "0.8"
 lmdb-sys = "0.8"
 parking_lot = "0.11.0"
-rand = "0.7"
+rand = "0.7.3"
 safe_arith = { path = "../consensus/safe_arith" }
 serde = "1.0"
 serde_derive = "1.0"

slasher/service/Cargo.toml

@@ -14,6 +14,6 @@ slog = "2.5.2"
 slot_clock = { path = "../../common/slot_clock" }
 state_processing = { path = "../../consensus/state_processing" }
 task_executor = { path = "../../common/task_executor" }
-tokio = { version = "1.7.1", features = ["full"] }
+tokio = { version = "1.10.0", features = ["full"] }
 tokio-stream = "0.1.3"
 types = { path = "../../consensus/types" }