Update test suite for JRuby 9.2

.travis.yml

@@ -8,6 +8,7 @@ rvm:
   - 2.5
   - 2.6
   - 2.7
+  - jruby-9.2
   # optional
   - ruby-head
   - jruby-19mode

net-ldap.gemspec

@@ -33,5 +33,5 @@ the most recent LDAP RFCs (4510-4519, plutions of 4520-4532).}
   s.add_development_dependency("rake", "~> 10.0")
   s.add_development_dependency("rubocop", "~> 0.49.0")
   s.add_development_dependency("test-unit")
-  s.add_development_dependency("byebug")
+  s.add_development_dependency("byebug") unless RUBY_PLATFORM == "java"
 end

test/test_ldap.rb

@@ -1,4 +1,4 @@
-require 'test_helper'
+require_relative 'test_helper'
 
 class TestLDAPInstrumentation < Test::Unit::TestCase
   # Fake Net::LDAP::Connection for testing

test/test_ssl_ber.rb

@@ -30,10 +30,16 @@ def setup
   end
 
   def test_transmit_strings
+    omit "JRuby throws an error without a real socket"
+    omit_if RUBY_PLATFORM == "java"
+
     assert_equal "foo", transmit("foo")
   end
 
   def test_transmit_ber_encoded_numbers
+    omit "JRuby throws an error without a real socket"
+    omit_if RUBY_PLATFORM == "java"
+
     @to.write 1234.to_ber
     assert_equal 1234, @from.read_ber
   end