Implement the ZLib Compression of data

[adityachopra29]

NOTE: Solve issue #28 first.

Implement the functions which creates a genericCompression instance for Zlib compression and decompression.
It should return a 'writer function' to create a writer that compresses data, and
a 'reader function' to create a reader that decompresses data.

NOTE: The Zlib Compression requires a integer input for level of compression and a dictionary input for metadata, so dont forget that!

HINT: You can use the standard go implementation of Zlib algorithm