first pass at search_issues

Conflicts:
	github3/api.py
	github3/github.py
	tests/integration/test_github.py
Update cassette
Use a IssueSearchResult
Totally forgot to add the file
Re-organize the tests alphabetically
Add test for github3.search_issues
Refer to the right thing
Use correct language in tests too
Merge branch 'feature-new-search-api' into feature-users-search

Conflicts:
	github3/github.py
	github3/search/__init__.py
	tests/integration/test_api.py
	tests/integration/test_github.py