Update requirements.txt for testing.
Update requirements.txt for testing.

jayvdb/requests-oauthlib,sigmavirus24/requests-oauthlib,singingwolfboy/requests-oauthlib,lucidbard/requests-oauthlib,abhi931375/requests-oauthlib,jayvdb/requests-oauthlib,jsfan/requests-oauthlib,dongguangming/requests-oauthlib,elafarge/requests-oauthlib,gras100/asks-oauthlib,requests/requests-oauthlib