Implement Gem#remote_versions_for and #latest_version

Provides simple Polisher::VersionChecker-compliant interface
to query this target

Includes specs and missing specs for Gem#download_gem
Merge pull request #77 from ManageIQ/remote_gems

Implement Gem#remote_versions_for and #latest_version
Fix #83: Catch errors during analysis, set 'unknown' version (rev 1)

Now if there are errors when running a query against a specified
polisher target, polisher will gracefully catch and set version
to 'unknown' for that target/pkg

Updates gem_dep_checker to handle this edge case, specs still
need tbd for version_checker

Updated to incorporate rubocop & review feedback
Implement Koji#build (rev 1)

Added specs for change + stubbed out Koji#build logs method
Merge pull request #84 from ManageIQ/clone_err

Fix #83: Catch errors during analysis, set 'unknown' version
Merge pull request #78 from ManageIQ/koji_builds

Implement Koji#build
Fix #37: raise errors on build failures (rev 6)

Also handle a few edge cases / add some syntactic sugar.

Rebased against lastest master
Improve file detection / conversion during spec update

More edge cases are detected & handled though code could use
some cleaning up / refactoring and specs need to be written
Follow up fixes to tidy up code & make rubocop happy :-) (rev 3)

- prefixes %{gem_instdir} to non-special files when
  rpmizing them
- removes symlink to gem after building srpm
- cleans up style & componentizes operations
- fixes broken specs

Revised to make rubocop even happier!

Ignoring warning about predicate name as current version fits
operation better imo
Add specs for some newly added features (rev 1)

Tidied up to resolve style warnings, ignoring note about void
'==' operator as that is intended rspec use