Step 16 fails when attempting to install composer

`Step 16 : RUN curl -s http://getcomposer.org/installer | php   && mv composer.phar /usr/local/bin/composer
 ---> Running in 092cbfec03c1
mv: cannot stat 'composer.phar': No such file or directory
ERROR: Service 'workspace' failed to build: The command '/bin/sh -c curl -s http://getcomposer.org/installer | php   && mv composer.phar /usr/local/bin/composer' returned a non-zero code: 1
`
