fix OAuth authentication version on Travis

Author: xabbuh

.travis.yml

@@ -21,7 +21,7 @@ matrix:
     - php: 5.4
       env: $COMPOSER_OPTIONS="--prefer-lowest --ignore-platform-reqs"
     - php: 5.6
-      env: PACKAGES="php-http/discovery:^1.0 php-http/guzzle6-adapter:^1.0 php-http/message:^1.0 xabbuh/oauth1-authentication:~0.1"
+      env: PACKAGES="php-http/discovery:^1.0 php-http/guzzle6-adapter:^1.0 php-http/message:^1.0 xabbuh/oauth1-authentication:~1.0"
     - php: 7.0
       env: xdebug="yes"