Updated mctools.py to read SRV Records

Updated MC Tools to read SRV Records that were implemented in Minecraft 1.3.1 
Requires module 'pydns' so please run 'sudo pip install pydns'
Fixed Host Error in mctools.py
Updated README.md to have a reference to 'pydns'
Updated requirements.txt to contain 'pydns'
Merge pull request #61 from KsaRedFx/develop

Updated mctools.py to read SRV Records