matplotlib 1.3.1 has requirement numpy>=1.5, but you'll have numpy 1.8.0rc1 which is incompatible

I was able to solve this with @Jacob's solution with some additional steps. I'll post it here for anyone else facing this.

1. Firstly as Jacob mentioned I downloaded and installed the latest Python 2.7.14+.

2. Executed sudo easy_install pip to install pip again

3. Executed sudo pip install numpy