Read vintage names and file paths to use for TSconnect.
A character string indicating a file.
file should be a character string indicating a
file that will be read. The file should have lines with two space separated
columns, the first indicating a name to be used for a vintage, e.g.,
2009-01-07, and the second indicating the path to the database file to use for
that vintage, e.g., /path/to/ets_2009-01-07.db. The file is read and the
result is a string that can be passed as the dbname to TSfame's TSconnect
a character vector with names