F_WRLCK not added to constants in Node.js 11

[alanshaw]

In Node.js 11:

$ node
> const fs = require('fs-ext')
undefined
> require('constants').F_WRLCK
undefined
> process.versions.node
'11.10.0'

In Node.js 10:

$ node
> const fs = require('fs-ext')
undefined
> require('constants').F_WRLCK
3
> process.versions.node
'10.15.1'

[alanshaw]

Also, require('constants') has been deprecated since Node.js 6 and it should be added to require('fs').constants or require('fs-ext').constants instead (I think the latter would make more sense).

[ikokostya]

o require('fs-ext').constants instead (I think the latter would make more sense).

I totally agree. Created separate issue for this #89