Update DOIT_SOA_ORDER_IFACE_L to v3

This PR updates the Order Line WSDL to v3. v3 of DOIT_SOA_ORDER_IFACE_L includes two new parameters, P_UNIT_PROMO_PRICE and P_PROMO_DISCOUNT_NAME for specifying promotional discounts.

Project version bumped to 7.0.0, and some Composer dependencies updated. Being in a refactoring mood, I also changed the datatypes in the OrderLineInputParametersMapper to properly reflect the datatype that InputParameters expects (which is really just a cosmetic change since we immediately set the correct values, but this is 'more correct' either way). I plan on doing the same for the rest of the classes and PHP7-ifying the project for its better type hinting, etc.

Please review: @ahoffmann @weizhong-wang @lloyd-carter @KJOYNER

src/main/edu/wisc/services/cbs/order/line/OrderLineInputParametersMapper.php

@@ -13,7+13,7 @@
 
     public static function toInputParameters(OrderLine $lineItem)
     {
         return (new InputParameters(
             0.0,
             "",
             0.0,
@@ -25,7+25,7 @@
             0.0,
             "",
             0.0,
-            new \DateTime(),
-            "",
+            0.0,
             "",
+            new \DateTime(),
             "",
             "",
             0.0,