Second beta release

• Renamed benchmark-action to benchmark-tracker
• Fixed CI for handling first run
• Upgraded codecov-action from v1 to v2 (https://about.codecov.io/blog/introducing-codecovs-new-uploader/)
• Changed fetching of gh-pages branch to use GitHub token (benchmark-action/github-action-benchmark#38)
• Added support for Benchmark.Net (benchmark-action/github-action-benchmark#34)
• Removed mention of PERSONAL_GITHUB_TOKEN (benchmark-action/github-action-benchmark#49)
• Fixed parsing Rust benchmark lines that include MB/s (benchmark-action/github-action-benchmark#50)
• Added support for long benchmark names in Catch2 (benchmark-action/github-action-benchmark#46)
• Updated dependencies