Filter out the /spec/ directory from simplcov

# Why?

 * Our code coverage tool (simplecov) was measuring the test coverage of our test code. Not only does that not make sense, it also skews our test coverage percentage.

# What Changed?

 * Added `/spec/` filter to simple cov.
 * We're at about 68% right now

File |  % covered Lines
lib/database/dbaccess_commands.rb | 32.26 %
lib/database/dbaccess_measurements.rb | 40.0 %
lib/database/dbaccess_logs.rb | 47.62 %
lib/database/dbaccess.rb  | 78.75 %
lib/database/dbaccess_parameters.rb | 90.67 %
lib/database/dbaccess_refreshes.rb  | 95.0 %

everything in the `model` directory was at 100%