Added fix for varargs methods incorrectly being flagged as transient and not tracked

This PR extends the list of modifiers to support varargs methods.

Java uses the same code (0x00000080) to represent both java.lang.reflect.Modifier#TRANSIENT and java.lang.reflect.Modifier#VARARGS.

This means that varargs methods are incorrectly flagged as being transient (in com.ryantenney.metrics.spring.AnnotationFilter#matches(java.lang.reflect.Method)), and therefore skipped due to invalid modifiers.

The test case included has been confirmed to fail before the change to AnnotationFilter and succeed after that change.