Add "date" to type mapping

Author: ackintosh

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/PhpClientCodegen.java

@@ -90,6 +90,7 @@ public PhpClientCodegen() {
                         "float",
                         "string",
                         "object",
+                        "date",
                         "DateTime",
                         "mixed",
                         "number",
@@ -117,6 +118,7 @@ public PhpClientCodegen() {
         typeMapping.put("string", "string");
         typeMapping.put("byte", "int");
         typeMapping.put("boolean", "bool");
+        typeMapping.put("date", "\\DateTime");
         typeMapping.put("Date", "\\DateTime");
         typeMapping.put("DateTime", "\\DateTime");
         typeMapping.put("file", "\\SplFileObject");