Flux.jl/test
Iblis Lin c43bda019b TrackedArray: implement mean
```julia
julia> p
Tracked 2×3 Array{Float64,2}:
 1.0  3.0  5.0
 2.0  4.0  6.0
```

Before
```julia
julia> @benchmark Flux.Tracker.back!(sum($p, 2) ./ size($p, 2), ones(2, 1))
BenchmarkTools.Trial:
  memory estimate:  3.44 KiB
  allocs estimate:  75
  --------------
  minimum time:     20.438 μs (0.00% GC)
  median time:      21.239 μs (0.00% GC)
  mean time:        22.354 μs (1.68% GC)
  maximum time:     3.811 ms (98.51% GC)
  --------------
  samples:          10000
  evals/sample:     1
```

After
```julia
julia> @benchmark Flux.Tracker.back!(mean($p, 2), ones(2, 1))
BenchmarkTools.Trial:
  memory estimate:  1008 bytes
  allocs estimate:  21
  --------------
  minimum time:     5.973 μs (0.00% GC)
  median time:      6.310 μs (0.00% GC)
  mean time:        6.630 μs (1.96% GC)
  maximum time:     680.709 μs (97.28% GC)
  --------------
  samples:          10000
  evals/sample:     6
```
2017-10-30 16:21:02 +08:00
..
layers reorganise 2017-10-26 11:46:12 +01:00
runtests.jl reorganise 2017-10-26 11:46:12 +01:00
tracker.jl TrackedArray: implement mean 2017-10-30 16:21:02 +08:00
utils.jl organise tests 2017-08-19 20:20:20 +01:00