add oss community board auto-add workflow

[wagoodman]

Allows for automatically adding issues to the OSS community board

[github-actions[bot]]

Benchmark Test Results

Benchmark results from the latest changes vs base branch

``` latest: Pulling from library/ubuntu tar: Option --mtime: Treating date 'UTC 2019-09-16' as 2019-09-16 00:00:00 goos: linux goarch: amd64 pkg: github.com/anchore/stereoscope/pkg/file cpu: Intel(R) Xeon(R) Platinum 8272CL CPU @ 2.60GHz docker: │ ./.tmp/benchmark-9836343.txt │ │ sec/op │ TarIndex-2 42.21µ ± ∞ ¹ ¹ need >= 6 samples for confidence interval at level 0.95 │ ./.tmp/benchmark-9836343.txt │ │ B/op │ TarIndex-2 5.559Ki ± ∞ ¹ ¹ need >= 6 samples for confidence interval at level 0.95 │ ./.tmp/benchmark-9836343.txt │ │ allocs/op │ TarIndex-2 93.00 ± ∞ ¹ ¹ need >= 6 samples for confidence interval at level 0.95 pkg: github.com/anchore/stereoscope/test/integration │ ./.tmp/benchmark-9836343.txt │ │ sec/op │ SimpleImage_GetImage/docker-archive-2 1.423m ± ∞ ¹ SimpleImage_GetImage/oci-archive-2 1.368m ± ∞ ¹ SimpleImage_GetImage/oci-dir-2 947.0µ ± ∞ ¹ geomean 1.226m ¹ need >= 6 samples for confidence interval at level 0.95 │ ./.tmp/benchmark-9836343.txt │ │ B/op │ SimpleImage_GetImage/docker-archive-2 356.2Ki ± ∞ ¹ SimpleImage_GetImage/oci-archive-2 646.3Ki ± ∞ ¹ SimpleImage_GetImage/oci-dir-2 413.5Ki ± ∞ ¹ geomean 456.6Ki ¹ need >= 6 samples for confidence interval at level 0.95 │ ./.tmp/benchmark-9836343.txt │ │ allocs/op │ SimpleImage_GetImage/docker-archive-2 2.624k ± ∞ ¹ SimpleImage_GetImage/oci-archive-2 1.567k ± ∞ ¹ SimpleImage_GetImage/oci-dir-2 1.351k ± ∞ ¹ geomean 1.771k ¹ need >= 6 samples for confidence interval at level 0.95 docker: Error response from daemon: Get "http://localhost/v2/": dial tcp [::1]:80: connect: connection refused. │ ./.tmp/benchmark-9836343.txt │ │ sec/op │ SimpleImage_FetchSquashedContents/docker-archive-2 17.30µ ± ∞ ¹ ¹ need >= 6 samples for confidence interval at level 0.95 │ ./.tmp/benchmark-9836343.txt │ │ B/op │ SimpleImage_FetchSquashedContents/docker-archive-2 2.648Ki ± ∞ ¹ ¹ need >= 6 samples for confidence interval at level 0.95 │ ./.tmp/benchmark-9836343.txt │ │ allocs/op │ SimpleImage_FetchSquashedContents/docker-archive-2 21.00 ± ∞ ¹ ¹ need >= 6 samples for confidence interval at level 0.95 ```