Start to spec and implement MacbethAnalyzer

Create first version of MacbethAnalyzer that downloads an XML file from
a given source. Add MacbethAnalyzer execution to analyze_macbeth.
Spec and implement LineCounter and Speaker

Create LineCounter and Speaker, using nokogiri to parse a given XML
file. Create a snippet fixture of Macbeth XML that exercises all
conditions. Add LineCounter execution to MacbethAnalyzer.
Spec and implement ResultDisplay

Create ResultDisplay and use in MacbethAnalyzer, replacing faked
value.
Allow for multiple speakers speaking a set of lines

There can be more than one speaker per speech group, so update
LineCounter to apply lines to all the speakers, and update snippet XML
to once again exercise all conditions.
Add output file

The output of running 719 MACBETH
265 LADY MACBETH
212 MALCOLM
180 MACDUFF
135 ROSS
113 BANQUO
74 LENNOX
70 DUNCAN
62 First Witch
46 Porter
45 Doctor
41 LADY MACDUFF
39 HECATE
35 Sergeant
30 SIWARD
30 First Murderer
27 Third Witch
27 Second Witch
24 ALL
23 Gentlewoman
23 Messenger
21 ANGUS
21 Lord
20 Son
15 Second Murderer
12 MENTEITH
11 Old Man
11 CAITHNESS
10 DONALBAIN
8 Third Murderer
7 YOUNG SIWARD
5 Third Apparition
5 SEYTON
5 Servant
4 Second Apparition
3 Lords
2 First Apparition
2 Both Murderers
2 FLEANCE
1 ATTENDANT
1 Soldiers
Add LICENSE
Update README with instructions and notes