* Fixed test_plot_data_points to match given data
Some of the expected values in test_plot_data_points have extra digits. The second data point had a y value of 0.22047244100000002 instead of 0.220472441 as given in the csv data file. These cause errors with assertEqual. It works fine with just this change, but it is still checking floats for equality which could be brittle. I also modified the assert line to use np.testing.assert_almost_equal which checks lists in an element-by-element fashion with tolerance and should be more robust.
* fixed test_plot_lines
Question asks for regression line "Through the year 2050" but the expected lists stops at the y-value for 2049. Added datapoint for 2050 in both lines. assertEqual was throwing errors for differences in 10th digit, changing this to np.testing.assert_almost_equal checks the first 7 digits which is a more robust way to check a regression calculated value.
* Added numpy import at top
added numpy import at top for np.testing.assert_almost_equal
