* Closes#237 Bump base64 from 0.10.1 to 0.11.0
* Closes#241 Bump flate2 from 1.0.12 to 1.0.13
* Closes#245 Bump num-traits from 0.2.8 to 0.2.10
* Closes#248 Bump serde_json from 1.0.41 to 1.0.44
* Closes#249 Bump serde from 1.0.102 to 1.0.104
* Closes#251 Bump web-sys from 0.3.30 to 0.3.33
* Closes#254 Bump structopt from 0.3.3 to 0.3.7
* Bump cfg-if from 0.1.9 to 0.1.10
* `cargo update` all modules