Tonic usage example and fixes #103

Job	Run time
Code Coverage	43s
docs	25s
feature-checks	17s
fmt	10s
clippy	25s
test stable --no-default-features	23s
test stable	30s
test stable --all-features	1m 14s
test beta --no-default-features	38s
test beta	35s
test beta --all-features	1m 14s
test nightly --no-default-features	30s
test nightly	30s
test nightly --all-features	1m 8s
test 1.80 --no-default-features	20s
test 1.80	18s
	9m 20s

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