[ImgBot] Optimize images (travis-ci#1) (travis-ci#2257)

*Total -- 1,102.60kb -> 780.61kb (29.2%)

/images/migrate/github-token-new.png -- 207.12kb -> 60.13kb (70.97%)
/images/migrate/legacy-services-migration-github-apps.png -- 75.42kb -> 47.99kb (36.37%)
/images/migrate/travis-ci-github-app.png -- 86.87kb -> 56.88kb (34.52%)
/images/migrate/github-token-added.png -- 33.35kb -> 22.51kb (32.5%)
/images/migrate/travis-ci-profile-with-github-apps-integration.png -- 41.69kb -> 28.31kb (32.1%)
/images/migrate/github-app-repo.png -- 20.95kb -> 14.91kb (28.81%)
/images/migrate/gem-github-apps-activate.png -- 27.40kb -> 19.86kb (27.53%)
/images/migrate/travis-ci-token-profile-page.png -- 7.28kb -> 5.30kb (27.21%)
/user/images/oss-migration/migrated-repo-org.png -- 56.84kb -> 47.28kb (16.83%)
/images/notifications/slack-integration.png -- 46.04kb -> 38.59kb (16.18%)
/images/Projects_20140305_165324_20140305_165329.jpg -- 53.42kb -> 44.90kb (15.95%)
/images/Screenshot_20140305_164512_20140305_164517.jpg -- 77.59kb -> 66.23kb (14.64%)
/user/images/oss-migration/gapps-activate.png -- 105.51kb -> 90.82kb (13.92%)
/images/Backstop_Menubar_20140305_155352_20140305_155425.jpg -- 24.01kb -> 21.09kb (12.17%)
/user/images/oss-migration/locked-settings-org.png -- 79.22kb -> 70.19kb (11.4%)
/user/images/oss-migration/confirmation-modal.png -- 81.64kb -> 72.50kb (11.19%)
/user/images/oss-migration/migrated-warning.png -- 42.21kb -> 38.80kb (8.08%)
/user/images/oss-migration/repos-to-migrate.png -- 36.05kb -> 34.34kb (4.75%)

Author: PatMyron