rename variables named 'word' to 'token' in generate fn
Author: patrickvonplaten
Pull request: yes

Rename `word` to `token` in generate() function.

Comments:
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/3119?src=pr&el=h1) Report
> Merging [#3119](https://codecov.io/gh/huggingface/transformers/pull/3119?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/34de670dbe70a9ead31d0692ad9dc726d3ea4edb?src=pr&el=desc) will **decrease** coverage by `1.01%`.
> The diff coverage is `90%`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/3119/graphs/tree.svg?width=650&token=9qOlN6Hb1c&height=150&src=pr)](https://codecov.io/gh/huggingface/transformers/pull/3119?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #3119      +/-   ##
==========================================
- Coverage   77.84%   76.83%   -1.02%     
==========================================
  Files          98       98              
  Lines       16422    16422              
==========================================
- Hits        12784    12618     -166     
- Misses       3638     3804     +166
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/3119?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/modeling\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/3119/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ191dGlscy5weQ==) | `94.29% <90%> (-0.32%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_pytorch\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/3119/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9weXRvcmNoX3V0aWxzLnB5) | `8.72% <0%> (-81.21%)` | :arrow_down: |
| [src/transformers/modeling\_roberta.py](https://codecov.io/gh/huggingface/transformers/pull/3119/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ19yb2JlcnRhLnB5) | `85.71% <0%> (-10%)` | :arrow_down: |
| [src/transformers/modeling\_xlnet.py](https://codecov.io/gh/huggingface/transformers/pull/3119/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ194bG5ldC5weQ==) | `73.48% <0%> (-2.3%)` | :arrow_down: |
| [src/transformers/modeling\_ctrl.py](https://codecov.io/gh/huggingface/transformers/pull/3119/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ19jdHJsLnB5) | `96% <0%> (-2.23%)` | :arrow_down: |
| [src/transformers/modeling\_openai.py](https://codecov.io/gh/huggingface/transformers/pull/3119/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ19vcGVuYWkucHk=) | `80.2% <0%> (-1.35%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/3119/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl91dGlscy5weQ==) | `91.86% <0%> (+0.3%)` | :arrow_up: |

------

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> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/3119?src=pr&el=footer). Last update [34de670...2caa33f](https://codecov.io/gh/huggingface/transformers/pull/3119?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).


Good to merge for me