Zero planning rebased2

[mahmoud-a-ali]

added files:

• segment_planning.py: low-level planning, calculating time and jerk sign for each phase
• traj_plannig.py: check limits, type of motion, raise different error for different unfeasible cases
• plot_traj_segment.py: to be used plot the auto-generated tests
• test_traj_segment.py: add more test cases, complex motion cases where velocity direction changes, and unfeasible cases where the test expect an error of a certain type
• test_traj_segment_middle_points.py: to test pos/vel/acc/jrk values at each instant the segment_phase changes (should be within the limits p_max, v_max, a_max, j_max)
• generate_random_test_cases.py: to auto-generate random feasible test cases
• generate_execption_test_cases.py: to auto-generate random unfeasible/illogical test cases
• cubic_eq_roots.py: to find the minimum positive real root for cubic equation
• test_min_real_root_cubic_eq.py: to test the minimum positive real root for cubic equation -average_time_to_fit_traj_segmen: to plot execution time which needed to calculate jerk_sign_and_duration to fit non_zero segment

modified files:

• plot.py: add p_max limits, plot two horizental dot lines for -p_max, p_max
• init.py: to add new modues
• trajectory.py: change fit_seven_segment to new added module fit_seven_segment_type3

[jonbinney]

@mahmoud-a-ali this looks good! Let me try it out today, and then I'll merge.

[jonbinney]

Great work, @mahmoud-a-ali ! Merging.