0.1.4

Includes all changes in 0.1.3, but fixes CI to build properly. 0.1.3 changes included are:

• Changed how assert_lines checks the limits of lines (@nkorinek, #243)
• Changed changelog to an rst file. (@nkorinek, #266)
• Add a vignette for testing vector data plots. (@nkorinek, #208)
• Add pillow as a dev requirement (@lwasser, #253)
• Removed the m2r package from MatPlotCheck (@nkorinek, #247)
• Made assert_string_contains() accept a string instead of a list
  (@nkorinek, #53)
• Added functions to get and assert the midpoint values of bins in a
  histogram (@nkorinek, #184)
• Created tests for the autograde module (@nkorinek, #105)
• Created tests for the vector module (@nkorinek, #209)
• Created functions to test point geometries in VectorTester
  (@nkorinek, #176)
• made assert_string_contains() accept correct strings with spaces
  in them (@nkorinek, #182)
• added contributors file and updated README to remove that information
  (@nkorinek, #121)
• Changed tolerance functionality from relative tolerance to absolute
  tolerance. (@ryla5068, #234)
• Made checking line coverage optional for base.assert_line()
  (@ryla5068, #239)
• Fixed bugs involving line tests (@ryla5068, #239)
• Improved handling of datasets with different shapes in base.assert_xy() (@ryla5068, #233)
• Bug fix for handling object datatypes in base.assert_xy() (@ryla5068, #232)