make_lift should recognize PGC I/D variants

[ofrei]

1kG:

1       rs57589734      0       39741584        G       GCTT
1       rs71906760      0       39698705        GTTTTGTT        G
1       rs67966942      0       39711950        AAAGTT  A

PGC_SCZ_2014:

D       I8      39698705        1       chr1_39698705_D
D       I3      39707474        1       chr1_39707474_D
D       I6      39711950        1       chr1_39711950_D
D       I3      39714273        1       chr1_39714273_I
I2      D       39715857        1       chr1_39715857_I
I2      D       39716844        1       chr1_39716844_I
I2      D       39733604        1       chr1_39733604_D
I5      D       39736463        1       chr1_39736463_I
D       I4      39741584        1       chr1_39741584_I
I2      D       39742864        1       chr1_39742864_D

[ofrei]

I think solution is to lift PGC summary stats by

• lookup each D/I variant from PGC in the reference (e.i. add --ref param to sumstats.py lift)
• replacing A1/A2 from D/I codes to the actual allele codes
• replacing marker names with the actual rs#