Cleanup Waterfall, blimpy plotting, and regression tests
The Waterfall object ccurrently can only support the input of a Filterbank file. Therefore, it now diagnoses the following as an error:
- Missing input Filterbank path.
- Presence of a data_array.
- Presence of a header dict object (metadata).
If, in the future, issue #264 is resolved in terms of requirements, then the following might be the metadata/data input options:
- Input Filterbank path for a file containing both metadata and a data array.
- A metadata dict object + a data array matrix, both RAM-resident.