CMB code for the bumblebee gravity theory

Please see

R. Xu, D. Xu, L. Andersson, P. Amaro-Seoane, and L. Shao, Bumblebee cosmology: The FLRW solution and the CMB temperature anisotropy

for reference.

Usage:

1. Write input parameters in bumblebee_input_data.txt ($H_0, \Omega_{b0}, \Omega_{c0}, T_{\rm CMB}, n_s, \alpha, q_0$)
2. Run bumblebeecmb_1.nb (takes about 1 hr)
3. Run bumblebeecmb_2.py (takes about 1 hr)
4. bumblebee_cl_data.txt is the output for $l(l+1)C_l/2\pi$ vs. $l$