Bump yarn from 1.15.2 to 1.17.3

Bumps [yarn](https://github.com/yarnpkg/yarn) from 1.15.2 to 1.17.3.
- [Release notes](https://github.com/yarnpkg/yarn/releases)
- [Changelog](https://github.com/yarnpkg/yarn/blob/v1.17.3/CHANGELOG.md)
- [Commits](yarnpkg/yarn@v1.15.2...v1.17.3)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -33,6 +33,6 @@
         "tslint": "5.10.0",
         "typescript": "2.9.2",
         "typescript-eslint-parser": "16.0.0",
-        "yarn": "^1.15.2"
+        "yarn": "^1.17.3"
     }
 }

package.json

@@ -1996,7 +1996,7 @@ compressible@~2.0.13:
 
 compression@^1.5.2:
   version "1.7.2"
-  resolved "http://registry.npmjs.org/compression/-/compression-1.7.2.tgz#aaffbcd6aaf854b44ebb280353d5ad1651f59a69"
+  resolved "https://registry.npmjs.org/compression/-/compression-1.7.2.tgz#aaffbcd6aaf854b44ebb280353d5ad1651f59a69"
   integrity sha1-qv+81qr4VLROuygDU9WtFlH1mmk=
   dependencies:
     accepts "~1.3.4"
@@ -2957,7 +2957,7 @@ etag@~1.8.1:
 
 event-stream@~3.3.0:
   version "3.3.4"
-  resolved "http://registry.npmjs.org/event-stream/-/event-stream-3.3.4.tgz#4ab4c9a0f5a54db9338b4c34d86bfce8f4b35571"
+  resolved "https://registry.npmjs.org/event-stream/-/event-stream-3.3.4.tgz#4ab4c9a0f5a54db9338b4c34d86bfce8f4b35571"
   integrity sha1-SrTJoPWlTbkzi0w02Gv86PSzVXE=
   dependencies:
     duplexer "~0.1.1"
@@ -8218,7 +8218,7 @@ yarn-global@^1.1.0:
   dependencies:
     user-home "^2.0.0"
 
-yarn@^1.15.2:
-  version "1.15.2"
-  resolved "https://registry.yarnpkg.com/yarn/-/yarn-1.15.2.tgz#7a064ca81ca34235f16376ad2f796ed432f9e285"
-  integrity sha512-DhqaGe2FcYKduO42d2hByXk7y8k2k42H3uzYdWBMTvcNcgWKx7xCkJWsVAQikXvaEQN2GyJNrz8CboqUmaBRrw==
+yarn@^1.17.3:
+  version "1.17.3"
+  resolved "https://registry.yarnpkg.com/yarn/-/yarn-1.17.3.tgz#60e0b77d079eb78e753bb616f7592b51b6a9adce"
+  integrity sha512-CgA8o7nRZaQvmeF/WBx2FC7f9W/0X59T2IaLYqgMo6637wfp5mMEsM3YXoJtKUspnpmDJKl/gGFhnqS+sON7hA==