backend: Update benchmarks. Go 1.8rc3 OSX 10.11
backend: Update benchmarks. Go 1.8rc3 OSX 10.11

name                                      old time/op    new time/op    delta
ResourceArgs_PrepareForwardHeaders/All-4    1.00µs ± 2%    0.98µs ± 1%   -2.37%          (p=0.002 n=6+6)
ResourceArgs_PrepareForwardHeaders/Two-4     288ns ± 1%     270ns ± 1%   -6.18%          (p=0.002 n=6+6)
ResourceArgs_PrepareReturnHeaders/All-4     2.06µs ± 2%    1.95µs ± 1%   -5.25%          (p=0.004 n=5+6)
ResourceArgs_PrepareReturnHeaders/Two-4      738ns ± 4%     718ns ± 0%     ~             (p=0.338 n=6+6)
NewFetchShellExec_Parallel-4                4.52ms ±26%    2.66ms ± 1%  -41.06%          (p=0.002 n=6+6)
NewMemCache_Parallel/Cancellable-4          49.3µs ±21%    39.4µs ± 8%  -20.03%          (p=0.004 n=6+6)
NewMemCache_Parallel/Non__Cancel-4          32.5µs ±11%    31.2µs ± 3%     ~             (p=0.329 n=6+5)
NewRedis_Parallel/Cancellable-4             39.8µs ±21%    35.3µs ± 3%     ~             (p=0.082 n=6+5)
NewRedis_Parallel/Non__Cancel-4             37.8µs ±57%    24.6µs ± 2%  -34.88%          (p=0.004 n=6+5)

name                                      old alloc/op   new alloc/op   delta
ResourceArgs_PrepareForwardHeaders/All-4      624B ± 0%      624B ± 0%     ~     (all samples are equal)
ResourceArgs_PrepareForwardHeaders/Two-4     96.0B ± 0%     96.0B ± 0%     ~     (all samples are equal)
ResourceArgs_PrepareReturnHeaders/All-4       528B ± 0%      528B ± 0%     ~     (all samples are equal)
ResourceArgs_PrepareReturnHeaders/Two-4       448B ± 0%      448B ± 0%     ~     (all samples are equal)
NewFetchShellExec_Parallel-4                32.2kB ± 6%    31.8kB ± 2%     ~             (p=0.937 n=6+6)
NewMemCache_Parallel/Cancellable-4          3.42kB ± 1%    3.16kB ± 1%   -7.85%          (p=0.002 n=6+6)
NewMemCache_Parallel/Non__Cancel-4          2.51kB ± 0%    2.52kB ± 0%     ~             (p=0.463 n=6+6)
NewRedis_Parallel/Cancellable-4               736B ± 0%      720B ± 0%   -2.17%          (p=0.002 n=6+6)
NewRedis_Parallel/Non__Cancel-4               240B ± 0%      240B ± 0%     ~     (all samples are equal)

name                                      old allocs/op  new allocs/op  delta
ResourceArgs_PrepareForwardHeaders/All-4      2.00 ± 0%      2.00 ± 0%     ~     (all samples are equal)
ResourceArgs_PrepareForwardHeaders/Two-4      2.00 ± 0%      2.00 ± 0%     ~     (all samples are equal)
ResourceArgs_PrepareReturnHeaders/All-4       10.0 ± 0%      10.0 ± 0%     ~     (all samples are equal)
ResourceArgs_PrepareReturnHeaders/Two-4       5.00 ± 0%      5.00 ± 0%     ~     (all samples are equal)
NewFetchShellExec_Parallel-4                   104 ± 1%       108 ± 0%   +3.51%          (p=0.002 n=6+6)
NewMemCache_Parallel/Cancellable-4            42.0 ± 0%      40.0 ± 0%   -4.76%          (p=0.002 n=6+6)
NewMemCache_Parallel/Non__Cancel-4            33.0 ± 0%      33.0 ± 0%     ~     (all samples are equal)
NewRedis_Parallel/Cancellable-4               16.0 ± 0%      15.0 ± 0%   -6.25%          (p=0.002 n=6+6)
NewRedis_Parallel/Non__Cancel-4               8.00 ± 0%      8.00 ± 0%     ~     (all samples are equal)

corestoreio/caddy-esi,corestoreio/caddy-esi,SchumacherFM/caddyesi,corestoreio/caddy-esi,SchumacherFM/caddyesi,SchumacherFM/caddyesi