Support non integer sample rate. (swharden#60)

* Support non integer sample rate.

* Update SpectrogramGenerator.cs

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Co-authored-by: Aksel Haukanes <aksel.haukanes@wartsila.com>
Co-authored-by: Scott W Harden <swharden@gmail.com>

Spectrogram 1.6.1

Merge pull request swharden#48 from swharden/47

GetBitmap: add Rotate argument

Merge pull request swharden#45 from swharden/1.1.6

Spectrogram 1.1.6

Spectrogram 1.4.4

Merge pull request swharden#39 from swharden/fftsharp-1.1.2

upgrade dependencies

Spectrogram 1.4.2

Spectrogram 1.4.0

Spectrogram 1.3.0

Spectrogram 1.2.6