Merge branch...

Merge branch '123-hierarchical-mass-quadrupole-distribution-likelihood-fails-when-evaluating-noise_log_likelihood' into 'master'

Resolve "Hierarchical mass quadrupole distribution likelihood fails when evaluating noise_log_likelihood for power law distribution"

Closes #123

See merge request cwinpy/cwinpy!169

cwinpy/hierarchical.py

@@ -766,6 +766,9 @@ class PowerLawDistribution(BaseDistribution):
         elif np.any(value > maximum):
             return -np.inf
 
+        if maximum <= minimum:
+            return -np.inf
+
         # get log pdf
         logpdf = bilby.core.prior.PowerLaw(alpha, minimum, maximum).ln_prob(value)