fix: package.json & .snyk to reduce vulnerabilities (#47)

The following vulnerabilities are fixed with a Snyk patch:
- https://snyk.io/vuln/npm:debug:20170905

Latest report for rocketchat/rocket.chat.reactnative:
https://snyk.io/test/github/rocketchat/rocket.chat.reactnative

.snyk

@@ -0,0 +1,26 @@
+# Snyk (https://snyk.io) policy file, patches or ignores known vulnerabilities.
+version: v1.7.1
+ignore: {}
+# patches apply the minimum changes required to fix a vulnerability
+patch:
+  'npm:debug:20170905':
+    - react-native > connect > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - react-native > connect > express-session > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - react-native > connect > finalhandler > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - react-native > connect > morgan > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - react-native > connect > serve-index > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - react-native > connect > body-parser > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - react-native > connect > compression > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - react-native > connect > connect-timeout > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - react-native > connect > serve-static > send > debug:
+        patched: '2017-09-29T23:29:20.238Z'
+    - realm > extract-zip > debug:
+        patched: '2017-09-29T23:29:20.238Z'

package.json

@@ -11,7 +11,9 @@
     "ios": "react-native run-ios",
     "log-android": "react-native log-android",
     "android": "react-native run-android",
-    "storybook": "storybook start -p 7007"
+    "storybook": "storybook start -p 7007",
+    "snyk-protect": "snyk protect",
+    "prepare": "npm run snyk-protect"
   },
   "dependencies": {
     "babel-plugin-transform-decorators-legacy": "^1.3.4",
@@ -49,7 +51,8 @@
     "redux-saga": "^0.16.0",
     "regenerator-runtime": "^0.11.0",
     "remote-redux-devtools": "^0.5.12",
-    "strip-ansi": "^4.0.0"
+    "strip-ansi": "^4.0.0",
+    "snyk": "^1.41.1"
   },
   "devDependencies": {
     "@storybook/addon-storyshots": "^3.2.15",
@@ -80,6 +83,7 @@
       ".+\\.(css|styl|less|sass|scss|png|jpg|ttf|woff|woff2)$": "identity-obj-proxy"
     }
   },
+  "snyk": true,
   "engines": {
     "node": ">=8.x",
     "npm": ">=4.x",