Add a few precompiles

Author: timholy

src/ReferenceTests.jl

@@ -21,4 +21,11 @@ include("fileio.jl")
 include("equality_metrics.jl")
 include("render.jl")
 
+if Base.VERSION >= v"1.4.2" && ccall(:jl_generating_output, Cint, ()) == 1
+    @assert precompile(Tuple{Core.kwftype(typeof(test_reference)),NamedTuple{(:by,), Tuple{typeof(isequal)}},typeof(test_reference),String,Matrix{RGB{Float64}}})   # time: 0.4697069
+    @assert precompile(Tuple{Core.kwftype(typeof(test_reference)),NamedTuple{(:by,), Tuple{typeof(isequal)}},typeof(test_reference),String,Matrix{RGBA{Float64}}})   # time: 0.24671553
+    @assert precompile(Tuple{typeof(test_reference),File{DataFormat{:PNG}},Matrix{RGB{Float64}},Function,Nothing})   # time: 0.029915236
+    @assert precompile(Tuple{typeof(test_reference),File{DataFormat{:PNG}},Matrix{RGBA{Float64}},Function,Nothing})   # time: 0.013356352
+end
+
 end # module