Bump follow-redirects from 1.15.4 to 1.15.6 in /examples/wasm/www #1009

Job	Run time
Windows (stable, default features)	1m 23s
Ubuntu (stable, no default features)	21s
Ubuntu (stable, all features)	23s
Compute binary sizes	25s
Build benchmarks	1m 19s
Ubuntu (stable, default features)	25s
Ubuntu (nightly, no default features)	29s
Build documentation	29s
Ubuntu (nightly, all features)	36s
Fuzz test (fill_first_fit)	1m 22s
Ubuntu (nightly, default features)	32s
Fuzz test (fill_optimal_fit)	1m 21s
Build Wasm demo	30s
Fuzz test (fill_fast_path)	1m 23s
Fuzz test (wrap_first_fit)	1m 26s
Minimum supported Rust version (no default features)	41s
Fuzz test (wrap_optimal_fit)	1m 36s
Minimum supported Rust version (all features)	51s
Fuzz test (wrap_optimal_fit_usize)	1m 21s
Fuzz test (wrap_fast_path)	1m 27s
Minimum supported Rust version (default features)	42s
Fuzz test (unfill)	1m 20s
Fuzz test (refill)	1m 20s
Deploy Wasm demo	0s
	21m 42s

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