Add rspec to project

* create Gemfile and add rspec gem
* create empty spec dir
* set some default options in .rspec
Add possibility to download file from URI

* URI content is stored in @file_content
Add XmlParser and possibility to count lines by speaker
Add possibility to retrieve all speakers

* with speaker method in XmlParser object
ShakespeareAnalyzer can print correct output parsed from XML file
Replace net/http with open-uri and add proxy support
Change method how to find all speakers

Declared PERSONAS don't mach SPEAKER in SPEECHEs, for example

<PERSONA>Three Witches.</PERSONA>
vs.
<SPEAKER>First Witch</SPEAKER>
...

whole xml: http://www.ibiblio.org/xml/examples/shakespeare/macbeth.xml
shakespeare_analyzer.rb can be now run as script

* run it with `ruby lib/shakespeare_analyzer.rb`
Add forgotten file from previous commit
Add script output to repository

Analyzed file:
http://www.ibiblio.org/xml/examples/shakespeare/macbeth.xml