Improve emoteevBidAdapter (prebid#3673)

* Improve emoteevBidAdapter

** Squash several pending changes

- Improve test coverage
- Extreme programming: 100% test coverage
- Document important constants
- Extreme programming: document all functions
- Imperative shell, functional core
- Send events onBidWon and onTimeout
- Report GDPR relevance and consent

Code documentation uses JSDoc tags wherever possible. See the
following link for general explanation of the notation used:
https://github.com/google/closure-compiler/wiki/Annotating-JavaScript-for-the-Closure-Compiler

** Test coverage

- 100% Statements 110/110
- 100% Branches 55/55
- 100% Functions 28/28
- 100% Lines 99/99

** Integration tests

Tested against production endpoint with the possible combinations of
these following parameters:

- Browser:
  · Chrome Canary 75.0.3739.0
  · Firefox Developer Edition 67.0b3 (64-bit)
  · Safari version 12.0.3 (14606.4.5)
  · Tor Browser 8.0.6 (based on Mozilla Firefox 60.5.1esr)
- Integration page:
  · integrationExamples/gpt/hello_world_emoteev.html
  · https://jsfiddle.net/8aqotw1k/6/

Localhost test server launched with:
$ npm install && gulp serve

* Tentative CI fix for IE and Edge webGL test

https://circleci.com/gh/prebid/Prebid.js/2052

* Tentative CI fix for IE and Edge webGL test #2

* Give up on webGL tests

Has anybody an idea to make it pass?

https://circleci.com/gh/prebid/Prebid.js/2056

New test coverage:

- 94.5% Statements 103/109
- 98.18% Branches 54/55
- 100% Functions 28/28
- 93.88% Lines 92/98

* Avoid useless noice in diff

* Remove unallowed metric pixel ON_ADAPTER_CALLED

Author: piotr-yuxuan

integrationExamples/gpt/hello_world_emoteev.html

@@ -5,84 +5,79 @@
     <script async src="//www.googletagservices.com/tag/js/gpt.js"></script>
     <script type="text/javascript" src="../../build/dev/prebid.js" async></script>
     <script>
-        var sizes = [
-            [300, 250],
-            [250, 300],
-            [300, 600]
-        ];
-        var PREBID_TIMEOUT = 3000;
-        var FAILSAFE_TIMEOUT = 3000;
+      const sizes = [
+        [300, 250],
+        [250, 300],
+        [300, 600]
+      ];
+      const PREBID_TIMEOUT = 3000;
+      const FAILSAFE_TIMEOUT = 3000;
 
-        var adUnits = [{
-            code: '/19968336/header-bid-tag-1',
-            mediaTypes: {
-                banner: {
-                    sizes: sizes
-                }
-            },
-            bids: [{
-              bidder: 'emoteev',
-              params: {
-                adSpaceId: 5084,
-              }
-            }]
-        }];
+      const adUnits = [{
+        code: '/19968336/header-bid-tag-1',
+        mediaTypes: {
+          banner: {
+            sizes: sizes
+          }
+        },
+        bids: [{
+          bidder: 'emoteev',
+          params: {
+            adSpaceId: 5084,
+          }
+        }]
+      }];
 
-        // ======== DO NOT EDIT BELOW THIS LINE =========== //
-        var googletag = googletag || {};
-        googletag.cmd = googletag.cmd || [];
-        googletag.cmd.push(function () {
-            googletag.pubads().disableInitialLoad();
-        });
+      // ======== DO NOT EDIT BELOW THIS LINE =========== //
+      var googletag = googletag || {};
+      googletag.cmd = googletag.cmd || [];
+      googletag.cmd.push(function () {
+        googletag.pubads().disableInitialLoad();
+      });
 
-        var pbjs = pbjs || {};
-        pbjs.que = pbjs.que || [];
+      var pbjs = pbjs || {};
+      pbjs.que = pbjs.que || [];
 
-        pbjs.que.push(function () {
-            pbjs.addAdUnits(adUnits);
-            pbjs.requestBids({
-                bidsBackHandler: initAdserver,
-                timeout: PREBID_TIMEOUT
-            });
+      pbjs.que.push(function () {
+        pbjs.addAdUnits(adUnits);
+        pbjs.requestBids({
+          bidsBackHandler: initAdserver,
+          timeout: PREBID_TIMEOUT
         });
+      });
 
-        function initAdserver() {
-            if (pbjs.initAdserverSet) return;
-            pbjs.initAdserverSet = true;
-            googletag.cmd.push(function () {
-                pbjs.que.push(function () {
-                    pbjs.setTargetingForGPTAsync();
-                    googletag.pubads().refresh();
-                });
-            });
-        }
-
-
-        // in case PBJS doesn't load
-        setTimeout(function () {
-            console.log("prebid.js setTimeout");
-            initAdserver();
-        }, FAILSAFE_TIMEOUT);
-
+      function initAdserver() {
+        if (pbjs.initAdserverSet) return;
+        pbjs.initAdserverSet = true;
         googletag.cmd.push(function () {
-            googletag.defineSlot('/19968336/header-bid-tag-1', sizes, 'div-1')
-                .addService(googletag.pubads());
-            googletag.pubads().enableSingleRequest();
-            googletag.enableServices();
+          pbjs.que.push(function () {
+            pbjs.setTargetingForGPTAsync();
+            googletag.pubads().refresh();
+          });
         });
+      }
 
-    </script>
+      setTimeout(function () {
+        initAdserver();
+      }, FAILSAFE_TIMEOUT);
 
+      googletag.cmd.push(function () {
+        googletag.defineSlot('/19968336/header-bid-tag-1', sizes, 'div-1')
+          .addService(googletag.pubads());
+        googletag.pubads().enableSingleRequest();
+        googletag.enableServices();
+      });
+    </script>
 </head>
 
 <body>
 <h2>Basic Prebid.js Example</h2>
 <h5>Div-1</h5>
 <div id='div-1'>
     <script type='text/javascript'>
-        googletag.cmd.push(function () {
-            googletag.display('div-1');
-        });
+      googletag.cmd.push(function () {
+        googletag.display('div-1');
+      });
 
     </script>
 </div>