increased min model version from *68 to *72 (#309)

* increased min model version from *68 to *72

this removes support for FW8 projects. before, it was causing LfMerge to crash. now, doing this in LF displays the desired red box and maintains a good state for that user.

Author: josephmyers

src/LfMerge.Core.Tests/MainClassTests.cs

@@ -28,8 +28,8 @@ public void FixtureTearDown()
 
 		[TestCase("7000060", ExpectedResult = false)]
 		[TestCase("7000067", ExpectedResult = false)]
-		[TestCase("7000068", ExpectedResult = true)]
-		[TestCase("7000069", ExpectedResult = true)]
+		[TestCase("7000068", ExpectedResult = false)]
+		[TestCase("7000069", ExpectedResult = false)]
 		[TestCase("7000071", ExpectedResult = false)]
 		[TestCase("7000072", ExpectedResult = true)]
 		public bool IsSupportedModelVersion(string modelVersion)

src/LfMerge.Core/MagicStrings.cs

@@ -8,7 +8,7 @@ public static class MagicStrings
 	{
 		static MagicStrings()
 		{
-			MinimalModelVersion = 7000068;
+			MinimalModelVersion = 7000072;
 		}
 
 		// Environment variables used by LfMerge