Not able to install googleads-php-lib on Centos

[bhagwat@server1 googleads-php-lib-25.1.0]$ php composer.phar require googleads/googleads-php-lib

Using version ^25.1 for googleads/googleads-php-lib
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

Problem 1
- The requested package googleads/googleads-php-lib No version set (parsed as 1.0.0) is satisfiable by googleads/googleads-php-lib[No version set (parsed as 1.0.0)] but these conflict with your requirements or minimum-stability.


Solution

Issue was resolved after upgrading composer with below command

php composer.phar update

(Composer seems not to be able to detect the version of the library and thus cannot install the library of v25.1 as requested.)