Typo in docs

+ci
Merge pull request #195 from MayhemYDG/patch-1

Typo in docs
Remove dead Builder.prototype.option() function.

It was replaced with options().
Throw an error when an invalid operator is passed in the where clause generation.
Add the "unused" option in .jshintrc
Merge pull request #197 from MayhemYDG/patch-1

Remove dead Builder.prototype.option() function.
add connection termination listener
remove console logs
Merge pull request #199 from will123195/handle-disconnect

add connection termination listener
Add support for pure JS driver for PostgreSQL

As there is no way to tell `npm` to not compile native driver, we should use https://github.com/brianc/node-postgres-pure instead which is exactly the same library without native driver. Please take a look at project's homepage.
Merge pull request #200 from xaka/patch-2

Add support for pure JS driver for PostgreSQL
Quote Node versions.

Node versions in the Travis configuration should be quoted, otherwise yaml sees this as `0.1` rather than `0.10`. This currently works because Travis treats the unknown `0.1` as `latest`, which is `0.10`, but it'll stop doing what you expect once `0.12` is out.
Merge pull request #202 from rubenv/patch-1

Quote Node versions.
remove disconnected connection from the pool

log disconnects

test

test

test

test

clean up
Merge pull request #206 from will123195/handle-disconnect

remove disconnected connections from the pool
docs prep for release
release 0.5.9
Replaced push.apply() calls with custom concat() function so the V8 stack will not exhaust when a complex query is being processed
add .exec to the knex promise shim
docs prep for release