SFH bug fix, rewrite, and basic tests

.github/workflows/continuous_integration.yml

@@ -36,4 +36,10 @@ jobs:
         export PATH_TO_POSYDON=./
         export PATH_TO_POSYDON_DATA=./posydon/unit_tests/_data/
         export MESA_DIR=./
-        python -m pytest posydon/unit_tests/ --cov=posydon.config --cov=posydon.utils --cov=posydon.grids --cov-branch --cov-report term-missing --cov-fail-under=100
+        python -m pytest posydon/unit_tests/ --cov=posydon.utils \
+                                             --cov=posydon.config \
+                                             --cov=posydon.grids \
+                                             --cov=posydon.popsyn.star_formation_history \
+                                             --cov-branch \
+                                             --cov-report term-missing \
+                                             --cov-fail-under=100

posydon/popsyn/rate_calculation.py

@@ -14,12 +14,13 @@
 from astropy import units as u
 
 
-DEFAULT_MODEL = {
+DEFAULT_SFH_MODEL = {
     "delta_t": 100,  # Myr
     "SFR": "IllustrisTNG",
     "sigma_SFR": None,
-    "Z_max": 1.0,
-    "select_one_met": False,
+    "Z_max": None, # Zsun
+    "Z_min": None, # Zsun
+    "normalise": True, # normalise the SFR to 1
     "dlogZ": None,  # e.g, [np.log10(0.0142/2),np.log10(0.0142*2)]
     "Zsun": Zsun,
 }
@@ -150,7 +151,6 @@ def get_redshift_from_cosmic_time(t_cosm):
     return trained_tz_interp(t_cosm)
 
 
-
 def get_redshift_bin_edges(delta_t):
     """Compute the redshift bin edges.