docs: fix example code commas

Closes #80
docs: add installation instructions

closes #83
deps: istanbul@0.3.2
build: change capitalization of history file
deps: update testing dependencies
deps: cookie-signature@1.0.5
deps: debug@~2.0.0
docs: update badges
docs: link to license
Call session.touch instead of session.resetMaxAge
build: remove npmignore file
tests: add req.session.save() test
Do not resave already-saved session at end of request

closes #74
docs: i'm basically maintaining this
1.8.0
Prevent session prototype methods from being overwritten

fixes #85
Keep req.session.save non-enumerable
docs: fix non-https badge
1.8.1
deps: depd@0.4.5