add span enter and exit #337

	on: [push, pull_request, workflow_dispatch]

	name: CI

	jobs:
	test:
	name: Test
	runs-on: ubuntu-latest
	steps:
	- name: Checkout sources
	uses: actions/checkout@v2

	- name: Install stable toolchain
	uses: actions-rs/toolchain@v1
	with:
	profile: minimal
	toolchain: stable
	override: true

	- name: Run cargo test
	uses: actions-rs/cargo@v1
	with:
	command: test

	- name: Run basic example
	uses: actions-rs/cargo@v1
	with:
	command: run
	args: --example=basic test/test.c.instr.wasm "Test"

	- name: Run many example
	uses: actions-rs/cargo@v1
	with:
	command: run
	args: --example=many test/test.c.instr.wasm "Test"

	- name: Run OpenTelemetry STDOUT example
	run: \|
	cargo run --example=otel-stdout test/nested.c.instr.wasm > test.json
	cat test.json \
	\| head -n 1 \
	\| jq '.resourceSpans[].scopeSpans[].spans[0].attributes[0]' \
	\| jq '.key == "function_name", .value.stringValue == "_start"'

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