bug(GridIntersect): fixes #916 and #917 (#918)

* refactor(make-release): Software citation developed from version.py

Closes #727

* release: update mf6 v6.1.1 dfn and flopy mf6 classes (#1)

* docs(misc): clean up docstrings

* refactor(GridIntersect): fix error message
for unsupported methods

* bug(GridIntersect): fix #10
ensure one entry per grid cell in polygon intersection result
add test for this case

* bug(gridintersect): fixes #917

bug in structured mode where linestrings were not handled
correctly if they pass in and out of grid cell

Co-authored-by: jdhughes-usgs <jdhughes@usgs.gov>
Co-authored-by: Christian Langevin <langevin@usgs.gov>

README.md

@@ -3,11 +3,11 @@
 
 ### Version 3.3.1 — release candidate
 [![Build Status](https://travis-ci.org/modflowpy/flopy.svg?branch=develop)](https://travis-ci.org/modflowpy/flopy)
+[![Codacy Badge](https://app.codacy.com/project/badge/Grade/3424dc693f9042ffadc93086cd554e47)](https://www.codacy.com/gh/modflowpy/flopy?utm_source=github.com&utm_medium=referral&utm_content=modflowpy/flopy&utm_campaign=Badge_Grade)
+[![Coverage Status](https://coveralls.io/repos/github/modflowpy/flopy/badge.svg?branch=develop)](https://coveralls.io/github/modflowpy/flopy?branch=develop)
 [![Anaconda-Server Badge](https://anaconda.org/conda-forge/flopy/badges/installer/conda.svg)](https://conda.anaconda.org/conda-forge)
 [![Anaconda-Server Badge](https://anaconda.org/conda-forge/flopy/badges/version.svg)](https://anaconda.org/conda-forge/flopy)
 [![PyPI Version](https://img.shields.io/pypi/v/flopy.png)](https://pypi.python.org/pypi/flopy)
-[![Coverage Status](https://coveralls.io/repos/github/modflowpy/flopy/badge.svg?branch=develop)](https://coveralls.io/github/modflowpy/flopy?branch=develop)
-[![Codacy Badge](https://api.codacy.com/project/badge/Grade/b23a5edd021b4aa19e947545ab49e577)](https://www.codacy.com/app/jdhughes-usgs/flopy?utm_source=github.com&utm_medium=referral&utm_content=modflowpy/flopy&utm_campaign=Badge_Grade)
 [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/modflowpy/flopy.git/develop)
 
 Introduction

autotest/t065_test_gridintersect.py

@@ -841,6 +841,22 @@ def test_rect_grid_polygon_with_hole_shapely(rtree=True):
     return result
 
 
+def test_rect_grid_polygon_in_edge_in_cell(rtree=True):
+    # avoid test fail when shapely not available
+    try:
+        import shapely
+    except:
+        return
+    gr = get_rect_grid()
+    ix = GridIntersect(gr, method='vertex', rtree=rtree)
+    p = Polygon([(0., 5.), (3., 0.), (7., 0.),
+                 (10., 5.), (10., -1.), (0., -1.)])
+    result = ix.intersect_polygon(p)
+    assert len(result) == 1
+    assert result.areas.sum() == 15.
+    return result
+
+
 def test_tri_grid_polygon_outside(rtree=True):
     # avoid test fail when shapely not available
     try:

flopy/discretization/grid.py

@@ -51,7 +51,7 @@ class Grid(object):
     rotation : float
         rotation angle of model grid, as it is rotated around the origin point
 
-    Properties
+    Attributes
     ----------
     grid_type : enumeration
         type of model grid ('structured', 'vertex_layered',