Add oracle_client_local_oracle_zip_files_dir variable

Points to where the instant client zip files are located on the
local computer
Create oracle user and oinstall group if they don't exist
Use sudo explicitly for creating files in ORACLE_HOME
Add oracle_client_install_cx_oracle to govern install of cx_Oracle
Added CHANGELOG
Merge pull request #2 from aguynamedryan/feature/fixes

Feature/fixes