Change graph to use VecDeque instead of Vec

[JakeRoggenbuck]

test result: ok. 0 passed; 0 failed; 25 ignored; 0 measured; 0 filtered out; finished in 0.00s

 Running unittests src/bin/main.rs (target/release/deps/acs-dc3485a02a9f740e)

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

 Running benches/graph_benchmark.rs (target/release/deps/graph_benchmark-10ef0494cf4904d5)

Gnuplot not found, using plotters backend
update_all time: [1.8843 µs 1.8877 µs 1.8916 µs]
change: [-1.5603% -1.4057% -1.2381%] (p = 0.00 < 0.05)
Performance has improved.
Found 1 outliers among 100 measurements (1.00%)
1 (1.00%) high severe

update_one time: [1.9719 µs 1.9741 µs 1.9765 µs]
change: [-4.2962% -3.9499% -3.6376%] (p = 0.00 < 0.05)
Performance has improved.
Found 16 outliers among 100 measurements (16.00%)
3 (3.00%) low mild
4 (4.00%) high mild
9 (9.00%) high severe

clear_before time: [1.3533 ns 1.3537 ns 1.3543 ns]
change: [-0.4202% +0.2638% +1.3826%] (p = 0.68 > 0.05)
No change in performance detected.
Found 10 outliers among 100 measurements (10.00%)
6 (6.00%) high mild
4 (4.00%) high severe

plot time: [3.9584 µs 3.9604 µs 3.9627 µs]
change: [-2.2912% -2.1126% -1.9123%] (p = 0.00 < 0.05)
Performance has improved.
Found 14 outliers among 100 measurements (14.00%)
4 (4.00%) high mild
10 (10.00%) high severe