Resolve "in factors: getTopology()"

Closes #269 (closed)

hello_wolf/factor_range_bearing.h

@@ -48,6 +48,11 @@ class FactorRangeBearing : public FactorAutodiff<FactorRangeBearing, 2, 2, 1, 2,
             //
         }
 
+        virtual std::string getTopology() const override
+        {
+            return "LMK";
+        }
+
         template<typename T>
         bool operator ()(const T* const _p_w_r, // robot position
                          const T* const _o_w_r, // robot orientation