Merge pull request #256 from xukai92/kx/compat

Support a range of SpecialFuns versions

Author: Gaika

Project.toml

@@ -17,5 +17,5 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 [compat]
 DSP = "0.5.2,0.6"
 FFTW = "0.2.4,1"
-SpecialFunctions = "0.7,0.10"
+SpecialFunctions = "0.7,0.8,0.9,0.10"
 julia = "1"