Fix: Remove unused imports

Fix: Cache dependencies installed with composer between builds

Fix: Remove useless override

Fix: Use more appropriate assertion

Fix: Remove useless return statements

Fix: Move assignment of default values before condition

Fix: Inline variable

Enhancement: Configure phpunit to use color

Fix: Case mismatch

Fix: Remove unused parameters

Fix: Use trusty dist

chore(travis): run travis on PHP 7.1

fix(client): set the connection timeout as the timeout (like Guzzlev3)

fix(client): set the connection_timeout for Guzzle v3

Check ini_get is not disabled before using it

Basing off pull request 413, fixing tests

As described in #492, ini_get may often be disabled in production environments, causing warnings to be generated (and NULL) to be returned. This change checks that ini_get is usable (otherwise function_exists will return FALSE) before using it, preventing the warnings while introducing no functional change.

Keep Response statusCode as integer, not string

Performance updates for formatting values

Provides fluent interface

Adjusts the conditional logic when building the field XML to only call htmlspecialchars on unknown values.

Merge changelog to develop