Update ConsIndShock's init_lifecycle

[Mv77]

Solves #592.
Updates ConsIndShock's init_lifecylce set of parameters, using Cagetti's (2003) estimates for the income trajectory of a high-school graduate, Sabelhaus & Song's (2010) life profiles of income volatilities, and aNrm initial dispersion estimates from the 1995 SCF.

• Tests for new functionality/models or Tests to reproduce the bug-fix in code.
• Updated documentation of features that add new functionality.
• Update CHANGELOG.md with major/minor changes.

[sbenthall]

changelog?

[codecov-io]

Codecov Report

Merging #951 (a05cde9) into master (a9f10c3) will increase coverage by 0.42%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #951      +/-   ##
==========================================
+ Coverage   71.01%   71.43%   +0.42%     
==========================================
  Files          62       62              
  Lines        9129     9138       +9     
==========================================
+ Hits         6483     6528      +45     
+ Misses       2646     2610      -36     

Impacted Files	Coverage Δ
HARK/ConsumptionSaving/ConsIndShockModel.py	83.39% <100.00%> (+0.19%)	⬆️
...nsumptionSaving/tests/test_IndShockConsumerType.py	100.00% <100.00%> (ø)
...ptionSaving/tests/test_IndShockConsumerTypeFast.py	100.00% <100.00%> (ø)
HARK/Calibration/Income/IncomeTools.py	92.79% <0.00%> (+7.20%)	⬆️
HARK/datasets/life_tables/us_ssa/SSATools.py	60.86% <0.00%> (+60.86%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a9f10c3...a05cde9. Read the comment docs.

[Mv77]

Ready.