Fix RTD build triggering on travis.
Fix RTD build triggering on travis.

apache/libcloud,Scalr/libcloud,mistio/libcloud,erjohnso/libcloud,erjohnso/libcloud,techhat/libcloud,SecurityCompass/libcloud,mgogoulos/libcloud,apache/libcloud,ByteInternet/libcloud,Scalr/libcloud,mgogoulos/libcloud,StackPointCloud/libcloud,t-tran/libcloud,StackPointCloud/libcloud,mgogoulos/libcloud,pquentin/libcloud,mistio/libcloud,ZuluPro/libcloud,vongazman/libcloud,t-tran/libcloud,vongazman/libcloud,ByteInternet/libcloud,mistio/libcloud,techhat/libcloud,StackPointCloud/libcloud,apache/libcloud,illfelder/libcloud,erjohnso/libcloud,SecurityCompass/libcloud,ZuluPro/libcloud,pquentin/libcloud,samuelchong/libcloud,techhat/libcloud,ZuluPro/libcloud,Kami/libcloud,ByteInternet/libcloud,t-tran/libcloud,illfelder/libcloud,andrewsomething/libcloud,pquentin/libcloud,samuelchong/libcloud,vongazman/libcloud,andrewsomething/libcloud,SecurityCompass/libcloud,Kami/libcloud,Kami/libcloud,andrewsomething/libcloud,Scalr/libcloud,illfelder/libcloud,samuelchong/libcloud