Change dependency to classpath dependency.

Build script dependencies can't be compile dependencies.

Signed-off-by: Shevek <shevek@anarres.org>

README.md

@@ -18,7 +18,7 @@ into build/generated-sources/sablecc:
 
 	buildscript {
 		dependencies {
-			compile 'org.anarres.gradle:gradle-sablecc-plugin:[1.0.0,)'
+			classpath 'org.anarres.gradle:gradle-sablecc-plugin:[1.0.0,)'
 		}
 	}