Pipeline-csv

------------------

- Fix error in Defect mp_left_weld and mp_right_weld properties.

------------------

+ Added `Defect` properties :

- orient_mp: orientation for defect maximum depth point
- length: defect length in mm as integer
- number_at_pipe: defect number at pipe as integer

------------------

+ Add Orientation.from_degree helper

* Fix new lines in saved csv file

------------------

+ Library work with the results of analysis of in-line flaw detection data in the form of a CSV file.

------------------

- Fix error in Defect.to_right_weld property if defect has zero length.

------------------

- Orientation in minutes does not exceed 720 minutes.

+ File class method `at_folder`.

+ `is_marker` property for Row class.