Fixes #1942 - Modifies the Image saving parameters for better quality

[karlcow]

This PR fixes issue #1942

Proposed PR background

Some thumbnail images were blurry.
This is an attempt at improving the quality a little bit by adjusting size and filter.
This also upgrades the library version of Pillow.

[karlcow]

@miketaylr if we deploy this, I would like to have it deployed on staging first. To test the performance issues with our real setup.

[TravisBuddy]

Travis tests have failed

Hey @karlcow,
Please read the following log in order to understand the failure reason.
It'll be awesome if you fix what's wrong and commit the changes.

1st Build

npm run test:js -- --reporters="runner" --firefoxBinary=`which firefox`

> webcompat@ test:js /home/travis/build/webcompat/webcompat.com
> node ./tests/functional/_intern.js "--reporters=runner" "--firefoxBinary=/home/travis/firefox-latest/firefox/firefox"

Error: 
        ======================================================
        Intern checkServer Connection Error: Error: connect ECONNREFUSED 127.0.0.1:5000
        ======================================================
        
  at ClientRequest.<anonymous>  <tests/functional/lib/setup.js:55:9>
  at emitOne  <events.js:116:13>
  at ClientRequest.emit  <events.js:211:7>
  at Socket.socketErrorListener  <_http_client.js:387:9>
  at emitOne  <events.js:116:13>
  at Socket.emit  <events.js:211:7>
  at emitErrorNT  <internal/streams/destroy.js:64:8>
something bad happened inside intern.run()
{ Error: 
        ======================================================
        Intern checkServer Connection Error: Error: connect ECONNREFUSED 127.0.0.1:5000
        ======================================================
        
    at ClientRequest.<anonymous> (/home/travis/build/webcompat/webcompat.com/tests/functional/lib/setup.js:55:9)
    at emitOne (events.js:116:13)
    at ClientRequest.emit (events.js:211:7)
    at Socket.socketErrorListener (_http_client.js:387:9)
    at emitOne (events.js:116:13)
    at Socket.emit (events.js:211:7)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickCallback (internal/process/next_tick.js:180:9) reported: true }
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! webcompat@ test:js: `node ./tests/functional/_intern.js "--reporters=runner" "--firefoxBinary=/home/travis/firefox-latest/firefox/firefox"`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the webcompat@ test:js script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/travis/.npm/_logs/2018-08-09T17_33_24_707Z-debug.log

[miketaylr]

I would like to have it deployed on staging first. To test the performance issues with our real setup.

@karlcow deployed to staging!

[webcompat.com] out: Installing collected packages: Pillow
[webcompat.com] out:   Found existing installation: Pillow 4.0.0
[webcompat.com] out:     Uninstalling Pillow-4.0.0:
[webcompat.com] out:       Successfully uninstalled Pillow-4.0.0
[webcompat.com] out: Successfully installed Pillow-5.2.0

[miketaylr]

(also re-kicked travis)

[miketaylr]

Changes LGTM, feel free to merge and add the changelog label if you think it's an improvement.

[karlcow]

deployed to staging!

Thanks.
I did a last test
https://staging.webcompat.com/issues/1642
and it went well. Let's deployed this.

3.9 Mo (2222x2388) to 172K (with a 1024, HAMMING).