rb-bioruby depends on nonexistent ports rb-dbd-mysql and rb-dbd-pg

[ryandesign (Ryan Carsten Schmidt)]

rb-bioruby declares dependencies on rb-dbd-mysql and rb-dbd-pg but no such ports exist.

$ port lint rb-bioruby +mysql +postgres
--->  Verifying Portfile for rb-bioruby
Warning: Variant mysql does not have a description
Warning: Variant postgres does not have a description
Error: Unknown dependency: rb-dbd-mysql
Error: Unknown dependency: rb-dbd-pg
--->  2 errors and 2 warnings found.

[cooljeanius (Eric Gallager)]

Fuller lint output:

$ port -v lint --nitpick rb-bioruby +mysql+postgres
--->  Verifying Portfile for rb-bioruby
OK: Found PortSystem 1.0
OK: Found PortGroup ruby-1.0
OK: Found required variable: name
OK: Found required variable: version
OK: Found required variable: description
OK: Found required variable: long_description
OK: Found required variable: categories
OK: Found required variable: maintainers
OK: Found required variable: platforms
OK: Found required variable: homepage
OK: Found required variable: master_sites
OK: Found required variable: checksums
OK: Found required variable: license
OK: Found optional variable: epoch
OK: Found optional variable: revision
OK: Found platform: darwin
OK: Found primary category: ruby
Warning: Variant mysql does not have a description
OK: Found variant: mysql
Warning: Variant postgres does not have a description
OK: Found variant: postgres
OK: Found dependency: ruby
OK: Found dependency: rb-bdb
OK: Found dependency: rb-http-access2
Error: Unknown dependency: rb-dbd-mysql
Error: Unknown dependency: rb-dbd-pg
Warning: missing recommended checksum type: rmd160
Warning: missing recommended checksum type: sha256
Warning: missing recommended checksum type: size
Warning: checksum type is insecure on its own: md5
OK: Portfile parent directory matches primary category
OK: Portfile directory matches port name
--->  2 errors and 6 warnings found.