Add Adoppler bidder support. (prebid#1186)

* Add Adoppler bidder support.

* Address code review comments. Use JSON-templates for testing.

* Fix misprint; Add url.PathEscape call for adunit URL parameter.

Author: vchimishuk

adapters/adoppler/adopplertest/exemplary/multibid.json

@@ -0,0 +1,60 @@
+{"mockBidRequest": {"id": "req1",
+                    "imp":[{"id": "imp1",
+                            "banner": {"w": 100,
+                                       "h": 200},
+                            "ext": {"bidder": {"adunit": "unit1"}}},
+                           {"id": "imp2",
+                            "video": {"minduration": 120,
+                                      "mimes": ["video/mp4"]},
+                            "ext": {"bidder": {"adunit": "unit2"}}},
+                           {"id": "imp3",
+                            "native": {"request": "{}"},
+                            "ext": {"bidder": {"adunit": "unit3"}}}]},
+ "httpCalls": [{"expectedRequest": {"uri": "http://adoppler.com/processHeaderBid/unit1",
+                                    "body": {"id": "req1-unit1",
+                                        "imp": [{"id": "imp1",
+                                                 "banner": {"w": 100, "h": 200},
+                                                 "ext": {"bidder": {"adunit": "unit1"}}}]}},
+                "mockResponse": {"status": 200,
+                                 "body": {"id": "req1-imp1-resp1",
+                                          "seatbid": [{"bid": [{"id": "req1-imp1-bid1",
+                                                                "impid": "imp1",
+                                                                "price": 0.12,
+                                                                "adm": "<b>a banner</b>"}]}],
+                                          "cur": "USD"}}},
+               {"expectedRequest": {"uri": "http://adoppler.com/processHeaderBid/unit2",
+                                    "body": {"id": "req1-unit2",
+                                        "imp": [{"id": "imp2",
+                                                 "video": {"minduration": 120,
+                                                           "mimes": ["video/mp4"]},
+                                                 "ext": {"bidder": {"adunit": "unit2"}}}]}},
+                "mockResponse": {"status": 200,
+                                 "body": {"id": "req1-imp2-resp2",
+                                          "seatbid": [{"bid": [{"id": "req1-imp2-bid1",
+                                                                "impid": "imp2",
+                                                                "price": 0.24,
+                                                                "adm": "<VAST />",
+                                                                "cat": ["IAB1", "IAB2"],
+                                                                "ext": {"ads": {"video": {"duration": 121}}}}]}],
+                                          "cur": "USD"}}},
+               {"expectedRequest": {"uri": "http://adoppler.com/processHeaderBid/unit3",
+                                    "body": {"id": "req1-unit3",
+                                        "imp": [{"id": "imp3",
+                                                 "native": {"request": "{}"},
+                                                 "ext": {"bidder": {"adunit": "unit3"}}}]}},
+                "mockResponse": {"status": 204,
+                                 "body": ""}}],
+ "expectedBidResponses": [{"currency": "USD",
+                           "bids": [{"bid": {"id": "req1-imp1-bid1",
+                                             "impid": "imp1",
+                                             "price": 0.12,
+                                             "adm": "<b>a banner</b>"},
+                                     "type": "banner"}]},
+                          {"currency": "USD",
+                           "bids": [{"bid": {"id": "req1-imp2-bid1",
+                                             "impid": "imp2",
+                                             "price": 0.24,
+                                             "adm": "<VAST />",
+                                             "cat": ["IAB1", "IAB2"],
+                                             "ext": {"ads": {"video": {"duration": 121}}}},
+                                     "type": "video"}]}]}

adapters/adoppler/adopplertest/exemplary/no-bid.json

@@ -0,0 +1,13 @@
+{"mockBidRequest": {"id": "req1",
+                    "imp":[{"id": "imp1",
+                            "banner": {"w": 100,
+                                       "h": 200},
+                            "ext": {"bidder": {"adunit": "unit1"}}}]},
+ "httpCalls": [{"expectedRequest": {"uri": "http://adoppler.com/processHeaderBid/unit1",
+                                    "body": {"id": "req1-unit1",
+                                        "imp": [{"id": "imp1",
+                                                 "banner": {"w": 100, "h": 200},
+                                                 "ext": {"bidder": {"adunit": "unit1"}}}]}},
+                "mockResponse": {"status": 204,
+                                 "body": ""}}],
+ "expectedBidResponses": []}