mdbr 0.1.2

This release provides for an R interface to three features of the MDB Tools:

1. mdb-schema as mdb_schema() to produce a readr::spec()
2. mdb-export as export_mdb() to create strings or files
3. mdb-tables as mdb_tables() to list tables as a vector

The read_mdb() function combines all three tools to read tables as data frame.