Strip out old code

All of these files have been moved to either:

- https://github.com/sigp/lighthouse-beacon
- https://github.com/sigp/lighthouse-validator
- https://github.com/sigp/lighthouse-common

For rationale, see: https://github.com/sigp/lighthouse/issues/197

eth2/utils/vec_shuffle/src/rng.rs

@@ -1,90 +0,0 @@
-use super::hashing::hash;
-
-const SEED_SIZE_BYTES: usize = 32;
-const RAND_BYTES: usize = 3; // 24 / 8
-const RAND_MAX: u32 = 16_777_215; // 2 ** (rand_bytes * 8) - 1
-
-/// A pseudo-random number generator which given a seed
-/// uses successive blake2s hashing to generate "entropy".
-pub struct ShuffleRng {
-    seed: Vec<u8>,
-    idx: usize,
-    pub rand_max: u32,
-}
-
-impl ShuffleRng {
-    /// Create a new instance given some "seed" bytes.
-    pub fn new(initial_seed: &[u8]) -> Self {
-        Self {
-            seed: hash(initial_seed),
-            idx: 0,
-            rand_max: RAND_MAX,
-        }
-    }
-
-    /// "Regenerates" the seed by hashing it.
-    fn rehash_seed(&mut self) {
-        self.seed = hash(&self.seed);
-        self.idx = 0;
-    }
-
-    /// Extracts 3 bytes from the `seed`. Rehashes seed if required.
-    fn rand(&mut self) -> u32 {
-        self.idx += RAND_BYTES;
-        if self.idx >= SEED_SIZE_BYTES {
-            self.rehash_seed();
-            self.rand()
-        } else {
-            int_from_byte_slice(&self.seed, self.idx - RAND_BYTES)
-        }
-    }
-
-    /// Generate a random u32 below the specified maximum `n`.
-    ///
-    /// Provides a filtered result from a higher-level rng, by discarding
-    /// results which may bias the output. Because of this, execution time is
-    /// not linear and may potentially be infinite.
-    pub fn rand_range(&mut self, n: u32) -> u32 {
-        assert!(n < RAND_MAX, "RAND_MAX exceed");
-        let mut x = self.rand();
-        while x >= self.rand_max - (self.rand_max % n) {
-            x = self.rand();
-        }
-        x % n
-    }
-}
-
-/// Reads the next three bytes of `source`, starting from `offset` and
-/// interprets those bytes as a 24 bit big-endian integer.
-/// Returns that integer.
-fn int_from_byte_slice(source: &[u8], offset: usize) -> u32 {
-    (u32::from(source[offset + 2]))
-        | (u32::from(source[offset + 1]) << 8)
-        | (u32::from(source[offset]) << 16)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_shuffling_int_from_slice() {
-        let mut x = int_from_byte_slice(&[0, 0, 1], 0);
-        assert_eq!((x as u32), 1);
-
-        x = int_from_byte_slice(&[0, 1, 1], 0);
-        assert_eq!(x, 257);
-
-        x = int_from_byte_slice(&[1, 1, 1], 0);
-        assert_eq!(x, 65793);
-
-        x = int_from_byte_slice(&[255, 1, 1], 0);
-        assert_eq!(x, 16711937);
-
-        x = int_from_byte_slice(&[255, 255, 255], 0);
-        assert_eq!(x, 16777215);
-
-        x = int_from_byte_slice(&[0x8f, 0xbb, 0xc7], 0);
-        assert_eq!(x, 9419719);
-    }
-}