message: Remove unused imports in Boolean.
diff: @@ -2,7 +2,6 @@ use pairing::{
  Engine,
  Field,
  PrimeField,
  - PrimeFieldRepr,
  BitIterator
  };
  @@ -506,10 +505,9 @@ impl From<AllocatedBit> for Boolean {
  #[cfg(test)]
  mod test {
  - use rand::{SeedableRng, Rand, XorShiftRng};
  use bellman::{ConstraintSystem};
  use pairing::bls12_381::{Bls12, Fr};
  - use pairing::{Field, PrimeField, PrimeFieldRepr, BitIterator};
  + use pairing::{Field, PrimeField};
  use ::circuit::test::*;
  use super::{
  AllocatedBit,
  