Adding unit tests (#3515)

webapp/package.json

@@ -18,7 +18,7 @@
     "keymirror": "0.1.1",
     "marked": "mattermost/marked#12d2be4cdf54d4ec95fead934e18840b6a2c1a7b",
     "match-at": "0.1.0",
-    "mattermost": "mattermost/mattermost-javascript#c72a75ca4ac135e2d476fc048ef7adc450e6739f",
+    "mattermost": "mattermost/mattermost-javascript#5815f14f0d1960aa4c99797b09d949d2959eb24f",
     "object-assign": "4.1.0",
     "perfect-scrollbar": "0.6.11",
     "react": "15.0.2",