Fetching relevants position embeddings instead of all. May increase s…

[hammad26]

Hi
Relevant position embeddings were only the first one and last one, but all were being calculated. I updated the code to focus only on relevant position embeddings (first and last one). I am hoping that it will improve speed and will also save some memory as well.

[hammad26]

Hi
Decoder part has some serious issue with imports. Corrected the imports and also, beam_size argument was commented in decoder but was being used at the time of model creation. Fixed that as well.

[SuperSupermoon]

Thanks for correcting the typo.