Add explicit dependency on isaac >= 0.1.2

Something depends on isaac 0.1.0, but that version doesn't compile on Nim 0.16
and above. Until the transitive dependancy is updated, ask for at least 0.1.2.

ptk.nimble

@@ -1,6 +1,6 @@
 # Package
 
-version       = "0.9.0"
+version       = "0.10.0"
 author        = "Jonathan Bernard"
 description   = "Personal Time Keeper"
 license       = "MIT"
@@ -8,5 +8,5 @@ bin           = @["ptk"]
 
 # Dependencies
 
-requires @["nim >= 0.15.0", "docopt >= 0.6.4", "uuids", "langutils", "tempfile", "timeutils >= 0.2.0"]
+requires @["nim >= 0.15.0", "docopt >= 0.6.4", "uuids", "langutils", "tempfile", "timeutils >= 0.2.0", "isaac >= 0.1.2"]