Update documentation on target implementation

Update documentation on target implementation in `io.read.read()`.
Correct `import` statement to `zipfile` module

Correct `import` statement in `io.read` to load `zipfile` module, rather
than non-existent `zip` module.
Initial work to implement zip-archive handling

Initial work to implement zip-archive handling:

* New `fail_on_error` keyword argument to allow for recursive data
  reading
* Differentiate compressed and archived filetypes in new keyword
  arguments to `detect_filetype()`; remove `valid_compressed_types`
  variable from module
* Set `detect_filetype()` to return `None` if detection failed (instead
  of previous treatment, which raised a runtime error)
Update documentation and handling of dot files

Update documentation in `detect_filetype()`.

Modify handling of dot files to return `None` in these cases.
Update header in preparation for main read tests

Update header in `test_read.py` in preparation for main read tests.
Add test CSV and TSV data

Add test CSV and TSV data, in preparation for main read tests.
Add (failing) test function for main read test

Add test to compare `io.read.read()` output to pandas `read_csv()`
output. Still to fully implement FSIC code: test currently fails.
Update `detect_filetype()` test for folder paths

Update `detect_filetype()` test to check for preceding folder paths.

Correct filename in (still-failing) `test_read_csv()` function.
Separate filename from filepath

Update `io.read.read()` to separate filename from filepath before
processing.
Re-implement filetype-detection function

Re-implement filetype-detection function to be shorter and clearer. Also
somewhat more general.

Remove `read()` function for future re-implementation (no change in
overall test status: continues to fail).
Remove duplicate `import` statement in doctest

Remove duplicate `import` statement in doctest for
`parser.code.translate()`.
Remove stray `print()` statements from test

Remove stray `print()` statements from test in
`FSIC/io/tests/test_read.py`.
Implement empty `read` function

Implement empty `read` function in `FSIC.io.read.py`.

Add test data for `io.read` to `setup.py`.
More work on `io.read.read()` function.

More work on `io.read.read()` function, to handle `method` argument, up
to the point where a `reader` function is required.
Rename docstring references: 'logical' > 'boolean'

Rename docstring references to 'logical' variables to 'boolean'.
Add tests for `parser.code.substitute()`

Add individual tests for `parser.code.substitute()` function.
Initial implementation of read code

Initial implement of code to read in data based on file format. First
implementation can handle CSV-type files only. Still to test
decompression handling.