Added Scientific Linux OS Name and Family Mappings

"ScientificLinux" has been added to _OS_NAME_MAP and map "ScientificLinux" to "RedHat" in _OS_FAMILY_MAP
tested on Scientific Linux CERN SLC release 5.9 (Boron)
it will be displayed like this and module 'pkg' will be work fine
```
# salt-call grains.items| grep ^os -A 1
os:
    ScientificLinux
os_family:
    RedHat
osarch:
    x86_64
oscodename:
    Boron
osfinger:
    Scientific Linux CERN SLC-5
osfullname:
    Scientific Linux CERN SLC
osmajorrelease:
    - 5
--
osrelease:
    5.9
```
instead of
```
# salt-call grains.items| grep ^os -A 1
os:
    Scientific  CERN SLC
os_family:
    Scientific  CERN SLC
oscodename:
    Boron
osfullname:
    Scientific Linux CERN SLC
osrelease:
    5.9
```