Raise a SystemExit when the user selects no match

Resolves #11
Test moving through filtered search results
Merge pull request #12 from marcomorain/select-no-matches

Raise a SystemExit when the user selects no match
Merge pull request #13 from marcomorain/test-filtered-search

Test moving through filtered search results
update spec name for World -> Search class rename
change delete key comment
add RVM version/gemset
add Gemfile
add .travis.yml
Merge branch 'travis'
specify initial search with -s
check arguments before reading input
update README with identifier search example
Merge branch 'search_argument'
vim command doesn't hide errors raised in `:e`
move up and down list with arrows (fixes #15)
rename variable
remove unused highlight variable/logic
remove unneeded parens
fix error message when ^Cing selecta in vim