added the function for optimal squeeze angle. Works for A+

Nice to have optimal filter cavity'ing for some things.. Not going to fix optimaloptimal until I'm certain I know how it is supposed to work (the calculation is substantially harder than for plain squeezing).

gwinc/noise/quantum.py

@@ -5,6 +5,12 @@ import scipy.constants
 import logging
 from ..struct import Struct
 
+def sqzOptimalSqueezeAngle(Mifo, eta):
+    vHD = np.array([[sin(eta), cos(eta)]])
+    H = getProdTF(vHD, Mifo)[0]
+    alpha = arctan(abs(H[1]), abs(H[0]))
+    return alpha
+
 
 def shotrad(f, ifo):
     """Quantum noise