Multifile

[pravirkr]

Major API change to support reading contiguous sigproc filterbank files.

• Moving all params related to the number of bits to a separate class.
• A separate fileio module with multifile Reader and single file Writer class.

Added digitize option to allow digitizing data before writing to file

• Based on nbits scale and offset similar to the dspsr implementation.
• Before digitizing, channels are rescaled/normalized in the given interval.
• Statistics from the previous interval is used to normalize data in the current read.
• For the first read, the gulp size is used as the interval.

Cleaned up Utils module. Added a logger function for future use.

[pravirkr]

Thanks, @telegraphic for the review. Merging now.

I will add more tests in another PR. Creating a release v0.5.5 for users to fallback. Changed digitize to quantize. However, keeping the (internal) param names as digi_*, (same as dspsr, to avoid confusion).

Re file format support, I am working on a PR for limited PSRFITS support (with astropy integration). I will open a separate issue to discuss this along with the roadmap ahead.

Yes, I think we should strictly follow PEP8 and in the next release, I aim to have the code fully typed, formatted and linted (following WPS style).