Issues238 - added rpm spec file

A pretty basic spec file, builds on CENTOS_LATEST x86 and x86_64, once you install the required packages, which was a bit of a pain since they are not in the softlayer repos :(


```
git clone https://github.com/softlayer/softlayer-python.git
cd softlayer-python
spectool -g -C /root/rpmbuild/SOURCES/  softlayer-python.spec
rpmbuild -ba softlayer-python.spec
rpm -ivh /root/rpmbuild/RPMS/i386/softlayer-python-master-2.el6.i386.rpm
```