Fixed failing test with case-insensitive enum values.

cli/src/main/groovy/com/jessebrault/ssg/StaticSiteGeneratorCli.groovy

@@ -13,7 +13,7 @@ final class StaticSiteGeneratorCli {
 
     static void main(String[] args) {
         System.exit(new CommandLine(StaticSiteGeneratorCli).with {
-            setCaseInsensitiveEnumValuesAllowed(true)
+            caseInsensitiveEnumValuesAllowed = true
             execute(args)
         })
     }

cli/src/test/groovy/com/jessebrault/ssg/StaticSiteGeneratorCliTests.groovy

@@ -8,7 +8,10 @@ import static org.junit.jupiter.api.Assertions.assertEquals
 final class StaticSiteGeneratorCliTests {
 
     private static void cliSmokeScreen(String... args) {
-        assertEquals(0, new CommandLine(StaticSiteGeneratorCli).execute(args))
+        assertEquals(0, new CommandLine(StaticSiteGeneratorCli).with {
+            caseInsensitiveEnumValuesAllowed = true
+            execute(args)
+        })
     }
 
     @Test