Add hooks framework

[tpcstld]

Add the ability to add hooks (both before and after function execution) onto the redshift_connection and activate_pipeline functions.

Add the execute command onto dataduct database. This will execute the SQL query into the redshift cluster specified by your config file.

Documentation for the hooks api is pending and will be added soon. :)

[coveralls]

Coverage increased (+0.16%) to 65.84% when pulling d83f1cbc2fbcf8925124807f2b3f41a1147aa500 on jj_hooks into 7b26c72749c96cdd511243e3e727ad594606c01f on develop.

[sb2nov]

Lets run it by PTB as this is a change away from what we converged upon so I want to keep him in the loop.

[coveralls]

Coverage decreased (-0.14%) to 65.54% when pulling 40e6411cb4a84631f078ae04d95277c946f5c745 on jj_hooks into 7b26c72749c96cdd511243e3e727ad594606c01f on develop.

[coveralls]

Coverage increased (+0.07%) to 65.74% when pulling 8a31b88f1e6defb1f6e86e402b8c1638c73ddff9 on jj_hooks into 7b26c72749c96cdd511243e3e727ad594606c01f on develop.

[sb2nov]

LGTM