Create the directory for dependencies database automatically

[OlegZee]

In case the database path is specified as in the following script the execution fails:

do xake {ExecOptions.Default with DbFileName = ".xaake/deps.xa"} {
   ...
}

Expected behavior:

• xake creates the folder (.xaake in the example above) automatically

Workaround:

• add CreateDirectory instruction as follows:

System.IO.Directory.CreateDirectory ".xaake" |> ignore

do xake {ExecOptions.Default with DbFileName = ".xaake/deps.xa"} {
    ....