make_data_set_extract_call: Creating the data call adress
In grlurton/dhisextractr: Extract data from DHIS for analysis purpose

make__data_set_extract_call creates a url used to call some data

1 2	make_data_set_extract_call(base_url, data_sets, org_unit, period, update_date = "2009-01-01")

`base_url`	The base url of the DHIS2 setting
`data_sets`	A table of data sets, as extracted
`org_unit`	A table of organization units, as extracted
`period_start`	Date of the beginning of the period from which to extract data
`period_end`	Date of the end of the period from which to extract data