mono version check will support 3 digit versions

src/NzbDrone.Core.Test/HealthCheck/Checks/MonoVersionCheckFixture.cs

@@ -62,5 +62,21 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
 
             Subject.Check().Should().BeNull();
         }
+
+        [Test]
+        public void should_return_null_when_mono_3_2_7()
+        {
+            GivenOutput("3.2.7");
+
+            Subject.Check().Should().BeNull();
+        }
+
+        [Test]
+        public void should_return_null_when_mono_3_2_1()
+        {
+            GivenOutput("3.2.1");
+
+            Subject.Check().Should().BeNull();
+        }
     }
 }

src/NzbDrone.Core/HealthCheck/Checks/MonoVersionCheck.cs

@@ -10,7 +10,7 @@ namespace NzbDrone.Core.HealthCheck.Checks
     {
         private readonly IProcessProvider _processProvider;
         private readonly Logger _logger;
-        private static readonly Regex VersionRegex = new Regex(@"(?<=\W)(?<version>\d+\.\d+\.\d+\.\d+)(?=\W)", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+        private static readonly Regex VersionRegex = new Regex(@"(?<=\W)(?<version>\d+\.\d+\.\d+(\.\d+)?)(?=\W)", RegexOptions.Compiled | RegexOptions.IgnoreCase);
 
         public MonoVersionCheck(IProcessProvider processProvider, Logger logger)
         {