chore(package): pin typescript version to MAJOR.MINOR

Minor ts versions can introduce new features that are not consumeable by earlier versions.
Increasing the minor version can therefore break compatbility with consumers that use older ts
versions. See Microsoft/typescript

package.json

@@ -76,7 +76,7 @@
     "tslint": "^5.7.0",
     "tslint-config-prettier": "^1.5.0",
     "tslint-eslint-rules": "^5.0.0",
-    "typescript": "^2.9.0",
+    "typescript": "~2.9.2",
     "webpack": "^4.10.1",
     "webpack-cli": "^3.0.3"
   },

yarn.lock

@@ -4510,9 +4510,9 @@ typedarray@^0.0.6:
   version "0.0.6"
   resolved "https://registry.yarnpkg.com/typedarray/-/typedarray-0.0.6.tgz#867ac74e3864187b1d3d47d996a78ec5c8830777"
 
-typescript@^2.9.0:
-  version "2.9.1"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.9.1.tgz#fdb19d2c67a15d11995fd15640e373e09ab09961"
+typescript@~2.9.2:
+  version "2.9.2"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.9.2.tgz#1cbf61d05d6b96269244eb6a3bce4bd914e0f00c"
 
 uglify-es@^3.3.4:
   version "3.3.9"