Update to new benchmarking framework (#126)

bw6_761/benches/bw6_761.rs

@@ -0,0 +1,16 @@
+use ark_algebra_bench_templates::*;
+
+use ark_bw6_761::{
+    fq::Fq, fq3::Fq3, fq6::Fq6, fr::Fr, g1::G1Projective as G1, g2::G2Projective as G2, BW6_761,
+};
+
+bench!(
+    Name = "BW6_761",
+    Pairing = BW6_761,
+    G1 = G1,
+    G2 = G2,
+    ScalarField = Fr,
+    G1BaseField = Fq,
+    G2BaseField = Fq3,
+    TargetField = Fq6,
+);