bundlerを使ったgemの管理を行うようにしました。
change testing framework from test/unit to minitest
define asser_raise for compatibility
raise error unless fail to drop table
fix how to asser for minitest
comment out attr_reader name_changed? cause of exit reading source file with following warning message
warning: instance vars on non-persistent Java type Java::OrgApacheDerbyImplJdbc::EmbedDatabaseMetaData40 (http://wiki.jruby.org/Persistence)
define assert_not_nil for compatibility
remove argument of test method (it might be a simple mistake)
skip a test of javax.swing.Timer. It must be fixed.
Merge pull request #3 from akm/develop

for JRuby-1.7.x