Crystal 1.5 warnings

[Jeremy Woertink]

Starting with Crystal 1.5, when you define a method that's abstract in a parent class, the arguments must be named the same to avoid issues with calling the method with named args:

In src/tar/reader.cr:387:16

 387 | def read(b : Bytes) : Int32
                ^
Warning: positional parameter 'b' corresponds to parameter 'slice' of the overridden method IO#read(slice : Bytes), which has a different name and may affect named argument passing

In src/tar/reader.cr:421:16

 421 | def read(b : Bytes) : Int32
                ^
Warning: positional parameter 'b' corresponds to parameter 'slice' of the overridden method IO#read(slice : Bytes), which has a different name and may affect named argument passing

In src/tar/writer.cr:366:17

 366 | def write(b : Bytes) : Nil
                 ^
Warning: positional parameter 'b' corresponds to parameter 'slice' of the overridden method IO#write(slice : Bytes), which has a different name and may affect named argument passing

In src/tar/writer.cr:394:17

 394 | def write(b : Bytes) : Nil
                 ^
Warning: positional parameter 'b' corresponds to parameter 'slice' of the overridden method IO#write(slice : Bytes), which has a different name and may affect named argument passing

In src/tar/writer.cr:133:23

 133 | if @hdr.flag == REGA
                       ^---
Warning: Deprecated Crystar::REGA. Use `REG` instead

A total of 5 warnings were found.

[Ali Naqvi]

Thank you @jwoertink . Your PR# #14 should be fixing this. If so can we have it closed?

[Jeremy Woertink]

Yup! Thanks 😄