Log Message:
py-gds: updated to 1.5.2

Version 1.5.2 (Feb 01, 2020)
Added support for importing GDSII files containing BOX elements.
Bug fix in GdsLibrary.extract (thanks collineps for finding the problem).

Version 1.5 (Dec 20, 2019)
New Cell.write_svg function to export an SVG image of the cell.
New GdsLibrary.new_cell function to quickly create and add cells to a library.
GdsLibrary.add can update references when a cell is overwritten.
Added GdsLibrary.remove to allow cells to be properly removed from libraries.
Added GdsLibrary.rename_cell to rename cells in libraries.
Added GdsLibrary.replace_references to easily replace referenced cells in libraries.
GdsLibrary.add can add dependencies recursively.
Iterating over GdsLibrary objects yields all its cells.
Iterating over Cell objects yield all its polygons, paths, labels and references.
Breaking change to *.to_gds functions in order to improve write efficiency (this \ 
should not be a problem for most users, since gdspy.write_gds and Cell.write_gds \ 
remain the same).
Breaking change: renamed GdsLibrary.cell_dict to GdsLibrary.cells.
Deprecated: gdspy.current_library, gdspy.write_gds, gdspy.fast_boolen, \ 
GdsLibrary.extract.
Bug fixes and better tests for FlexPath and RobustPath.

Version 1.4.3 (Nov 11, 2019)
Bug fix for FlexPath and RobustPath references.

Version 1.4.2 (Oct 01, 2019)
Bug fix in FlexPath.

Version 1.4.1 (Sep 20, 2019)
Bug fixes (thanks to DerekK88 and Sequencer for the patches).

Version 1.4 (May 18, 2019)
Revised documentation.
New FlexPath and RobustPath classes: more efficient path generation when using \ 
the original GDSII path specification.
New Curve class: SVG-like polygon creation.
Added PolygonSet.mirror (thanks to Daan Waardenburg for the contribution).
Added Path.bezier to create paths based on Bézier curves.
Added Path.smooth to create paths based on smooth interpolating curves.
Added get_gds_units to get units used in a GDSII file without loading.
Added get_binary_cells to load only the binary GDSII representation of cell from \ 
a file.
Added argument tolerance to Round, Path.arc, Path.turn, and Path.parametric to \ 
automatically control the number of points in the final polygons.
Added argument binary_cells to GDSII writing functions to support get_binary_cells.
Added argument rename_template to GdsLibrary.read_gds for flexible cell renaming \ 
(thanks to @yoshi74ls181 for the contribution).
Changed return value of slice to avoid creating empty PolygonSet.
Added argument timestamp to GDSII writing functions.
Improved Round to support creating ellipses.
Added support for unlimited number of points per polygon.
Added support for BGNEXTN and ENDEXTN when reading a GDSII file.
Polygon creation warnings are now controlled by poly_warnings.
Incorrect anchor in Label now raises an error, instead of emitting a warning.
Added correct support for radius in PolygonSet.fillet on a per-vertex basis.
Speed improvements in GDSII file generation (thanks to @fbeutel for the \ 
contribution) and geometry creation.
Font rendering example using matplotlib (thanks Hernan Pastoriza for the \ 
contribution).
Expanded test suite.

Version 1.3.2 (Mar 14, 2019)
Small fix for building on Mac OS X Mojave.