One test case for max-flow algorithm

test/edmonds_karp_test.cpp

 #include <catch2/catch.hpp>
 
 #include <gp-bnb/edmonds_karp.hpp>
+#include <gp-bnb/graph.hpp>
+#include <gp-bnb/metis_reader.hpp>
 
 // Tests for Edmonds-Karp Max Flow algorithm
 
 TEST_CASE("EdmondsKarpMaxFlow") {
+    
+    std::string graph_file = "../test/inputs/tiny_01.graph";
+    graph g = metis_reader().read(graph_file);
 
+    node_id source = 1;
+    node_id sink = 7;
+    edmonds_karp ek = edmonds_karp(g, source, sink);
+
+    ek.run();
+    int max_flow = ek.get_max_flow();
+
+    REQUIRE(max_flow == 2);
 }
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