drop support for Julia <v1.6

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "ToeplitzMatrices"
 uuid = "c751599d-da0a-543b-9d20-d0a503d91d24"
-version = "0.8.0"
+version = "0.9.0"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"
@@ -12,7 +12,7 @@ StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
 AbstractFFTs = "0.4, 0.5, 1"
 DSP = "0.7.7"
 StatsBase = "0.32, 0.33"
-julia = "1.0"
+julia = "1.6"
 
 [extras]
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"