Update to spec v0.11 (#959)

* Update process_final_updates() hysteresis computation

* Update core to v0.11.1

* Bump tags to v0.11.1

* Update docs and deposit contract

* Add compute_fork_digest

* Address review comments

Co-authored-by: Herman Alonso Junge <alonso.junge@gmail.com>

eth2/state_processing/src/common/get_attesting_indices.rs

@@ -3,7 +3,7 @@ use types::*;
 
 /// Returns validator indices which participated in the attestation, sorted by increasing index.
 ///
-/// Spec v0.10.1
+/// Spec v0.11.1
 pub fn get_attesting_indices<T: EthSpec>(
     committee: &[usize],
     bitlist: &BitList<T::MaxValidatorsPerCommittee>,

eth2/state_processing/src/common/get_base_reward.rs

@@ -3,7 +3,7 @@ use types::*;
 
 /// Returns the base reward for some validator.
 ///
-/// Spec v0.9.1
+/// Spec v0.11.1
 pub fn get_base_reward<T: EthSpec>(
     state: &BeaconState<T>,
     index: usize,

eth2/state_processing/src/common/get_indexed_attestation.rs

@@ -6,7 +6,7 @@ type Result<T> = std::result::Result<T, BlockOperationError<Invalid>>;
 
 /// Convert `attestation` to (almost) indexed-verifiable form.
 ///
-/// Spec v0.10.1
+/// Spec v0.11.1
 pub fn get_indexed_attestation<T: EthSpec>(
     committee: &[usize],
     attestation: &Attestation<T>,

eth2/state_processing/src/common/initiate_validator_exit.rs

@@ -3,7 +3,7 @@ use types::{BeaconStateError as Error, *};
 
 /// Initiate the exit of the validator of the given `index`.
 ///
-/// Spec v0.10.1
+/// Spec v0.11.1
 pub fn initiate_validator_exit<T: EthSpec>(
     state: &mut BeaconState<T>,
     index: usize,

eth2/state_processing/src/common/slash_validator.rs

@@ -4,7 +4,7 @@ use types::{BeaconStateError as Error, *};
 
 /// Slash the validator with index ``index``.
 ///
-/// Spec v0.10.1
+/// Spec v0.11.1
 pub fn slash_validator<T: EthSpec>(
     state: &mut BeaconState<T>,
     slashed_index: usize,