Update sapling-crypto crate to use ff crate

sapling-crypto/src/jubjub/edwards.rs

@@ -1,10 +1,4 @@
-use pairing::{
-    Field,
-    SqrtField,
-    PrimeField,
-    PrimeFieldRepr,
-    BitIterator
-};
+use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr, SqrtField};
 
 use super::{
     JubjubEngine,

sapling-crypto/src/jubjub/fs.rs

@@ -1,7 +1,9 @@
 use byteorder::{ByteOrder, LittleEndian};
-use pairing::{BitIterator, Field, PrimeField, SqrtField, PrimeFieldRepr, PrimeFieldDecodingError, LegendreSymbol};
-use pairing::LegendreSymbol::*;
-use pairing::{adc, sbb, mac_with_carry};
+use ff::{
+    adc, mac_with_carry, sbb, BitIterator, Field,
+    LegendreSymbol::{self, *},
+    PrimeField, PrimeFieldDecodingError, PrimeFieldRepr, SqrtField,
+};
 
 use super::ToUniform;
 

sapling-crypto/src/jubjub/mod.rs

@@ -17,12 +17,8 @@
 //! the Montgomery curve forms a group isomorphism, allowing points
 //! to be freely converted between the two forms.
 
-use pairing::{
-    Engine,
-    Field,
-    PrimeField,
-    SqrtField
-};
+use ff::{Field, PrimeField, SqrtField};
+use pairing::Engine;
 
 use group_hash::group_hash;
 

sapling-crypto/src/jubjub/montgomery.rs

@@ -1,10 +1,4 @@
-use pairing::{
-    Field,
-    SqrtField,
-    PrimeField,
-    PrimeFieldRepr,
-    BitIterator
-};
+use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr, SqrtField};
 
 use super::{
     JubjubEngine,

sapling-crypto/src/jubjub/tests.rs

@@ -6,7 +6,7 @@ use super::{
     edwards
 };
 
-use pairing::{
+use ff::{
     Field,
     PrimeField,
     PrimeFieldRepr,