N-API code coverage

[mhdawson]

• Version: master
• Platform: all
• Subsystem: n-api

Not a surprise but code coverage for n-api is lower than we'd like: https://coverage.nodejs.org/coverage-a5f91ab230c574d5/cxxcoverage._home_iojs_build_workspace_node-test-commit-linux-coverage_nodes_benchmark_out_.._src_node_api.cc.html

This probably was the cause for the 1.4% drop last night in the C++ coverage.

Opening this issue to that we focus on addressing this and include as part of our more comprehensive call to arms blog going out next week.

fyi @nodejs/n-api

[mhdawson]

Coverage is now up to 91.9% which is higher than the overall average, closing.