add alignment_projections property

See merge request !26

# Conflicts:
#	tomoscan/scanbase.py
#	tomoscan/test/test_scanbase.py

[doc] fix tutorials. Now EDFTomoScan.projections only return the none alignment projections. And there is  only 20 projections of those

# Conflicts:
#	tomoscan/scanbase.py

Rework flat field correction

See merge request !27

add property `estimated_cor_frm_motor`

See merge request !24

[scanbase] keep original behavior: flat_field_correction always return a list of nuloy array even if flat field correction fails

Frm tomwer to tomoscan2

Closes #3

See merge request !22

/close #3

add black hook

See merge request !21