Unable to install 0ci8 library on ruby 2.2.2p95 (windows 7) and connect to Oralce

i have looked into many Forums also in Ruby's one, am not able to install oci8. its shows following error..

D:\Ruby_WS>gem install ruby-oci8 -v 2.0.3 Building native extensions. This could take a while... ERROR: Error installing ruby-oci8: ERROR: Failed to build gem native extension. C:/Ruby22-x64/bin/ruby.exe -r ./siteconf20150730-4004-l0oo7f.rb extconf.rb checking for load library path... PATH... checking C:\Ruby22-x64\bin... no checking D:\app\BGH39173\product\11.2.0\client_1... yes D:/app/BGH39173/product/11.2.0/client_1/oci.dll looks like an instant client. checking for cc... ok checking for gcc... yes checking for LP64... no checking for ruby header... * extconf.rb failed * Could not create Makefile due to some reason, probably lack of necessary libraries and/or headers. Check the mkmf.log file for more details. You may need configuration options.

Provided configuration options: --with-opt-dir --without-opt-dir --with-opt-include --without-opt-include=${opt-dir}/include --with-opt-lib --without-opt-lib=${opt-dir}/lib --with-make-prog --without-make-prog --srcdir=. --curdir --ruby=C:/Ruby22-x64/bin/$(RUBY_BASE_NAME) --with-instant-client --without-instant-client C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:596:in check_ruby_header': Runti from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:552:ininit' from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:1001:in initialize' from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:343:innew' from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:343:in `get'

from extconf.rb:18:in `'

Error Message: uninitialized constant OraConf::Config Backtrace: C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:596:in check_ruby_header' C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:552:ininit' C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:1001:in initialize' C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:343:innew' C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3/ext/oci8/oraconf.rb:343:in `get'

extconf.rb:18:in `'

See: * http://ift.tt/1Iu3YYK * http://ift.tt/1DSaJhM

extconf failed, exit code 1

Gem files will remain installed in C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/ruby-oci8-2.0.3 for inspection. Results logged to C:/Ruby22-x64/lib/ruby/gems/2.2.0/extensions/x64-mingw32/2.2.0/ruby-oci8-2.0.3/gem_make.ou

D:\Ruby_WS>ruby -version ruby 2.2.2p95 (2015-04-13 revision 50295) [x64-mingw32] -e:1:in <main>': undefined local variable or methodrsion' for main:Object (NameError)

please help me..