Async tests running on dodgy Travis containers are not my friends

(closes #6391)

Default timeout of 2000 regularly exceeded, causing spurious test failures.
Even a random garbage collection pause can take more than 2 seconds.

test/spec/services/mapillary.js

@@ -100,7 +100,6 @@ describe('iD.serviceMapillary', function() {
         });
 
         it('loads multiple pages of image results', function(done) {
-            this.timeout(10000);
             var calls = 0;
             mapillary.on('loadedImages', function() {
                 server.respond();  // respond to new fetches
@@ -194,7 +193,6 @@ describe('iD.serviceMapillary', function() {
         });
 
         it('loads multiple pages of signs results', function(done) {
-            this.timeout(10000);
             var calls = 0;
             mapillary.on('loadedSigns', function() {
                 server.respond();  // respond to new fetches

test/spec/spec_helpers.js

@@ -22,6 +22,7 @@ iD.data.presets = {
 
 
 mocha.setup({
+    timeout: 10000,
     ui: 'bdd',
     globals: [
         '__onresize.tail-size',