We thank the anonymous referee for useful comments, which helped to clarify the paper. Some of the results in this paper have been derived using the HEALPix package. Parts of the cosmological analysis was made using Cosmo MC, CLASS and MontePython. C.H.-M. acknowledges financial support of the Spanish Ministry of Economy and Competitiveness via I+D project AYA-2015-66211-C2-2-P. CJM is supported by an FCT Research Professorship, contract reference IF/00064/2012, funded by FCT/MCTES (Portugal) and POPH/FSE. J.G.N. acknowledges financial support from the Spanish MINECO for a ‘Ramon y Cajal’ fellowship (RYC-2013-13256) and the I+D 2015 project AYA2015-65887-P (MINECO/FEDER).