Change way to describe bound for DSP.jl

(similar objective as previous commit, ensure DSP can be used with 8.x)

Author: RGerzaguet

Project.toml

@@ -14,7 +14,7 @@ Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
 Parameters = "0.12"
-DSP = ">=0.7, <0.9"
+DSP = "0.7 - 0.9"
 FFTW = "1.4.5"
 SpecialFunctions = "2.0"
 julia = "1.6"