Add apache::mod::info spec tests

This commit adds a series of rpsec-puppet tests for the
`apache::mod::info` class.
Merge remote-tracking branch 'trlinkin/info_enhancement' into info_enhancement
Update specs for current module layout
Only 0 (no changes) and 2 (successful) are valid exit codes
Merge pull request #218 from hunner/info_enhancement

apache::mod::info specs
Merge pull request #222 from hunner/system_exit_codes

Only 0 (no changes) and 2 (successful) are valid exit codes