Revert to regular BBHx install for tests

Author: titodalcanton

tox.ini

@@ -21,7 +21,7 @@ conda_deps =
 
 [bbhx]
 deps =
-    git+https://github.com/titodalcanton/BBHx.git@py39-and-cleanup; sys_platform == 'linux'
+    bbhx; sys_platform == 'linux'
     git+https://github.com/gwastro/BBHX-waveform-model.git; sys_platform == 'linux'
 conda_deps =
     liblapacke