Version detection in release entry file name should be a little bit m…

…ore strict

src/Squirrel/ReleaseEntry.cs

@@ -373,7 +373,7 @@ internal static ReleasePackage GetPreviousRelease(IEnumerable<ReleaseEntry> rele
         }
 
         static readonly Regex _suffixRegex = new Regex(@"(-full|-delta)?\.nupkg$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
-        static readonly Regex _versionStartRegex = new Regex(@"(^|[^\d])(0|[1-9]\d*)\.(0|[1-9]\d*)($|[^\d])", RegexOptions.Compiled);
+        static readonly Regex _versionStartRegex = new Regex(@"[\.-](0|[1-9]\d*)\.(0|[1-9]\d*)($|[^\d])", RegexOptions.Compiled);
 
         /// <summary>
         /// Takes a filename such as 'My-Cool3-App-1.0.1-build.23-full.nupkg' and separates it into