Merge pull request #12713 from vector-im/travis/yarn-cleanup

Remove stuff that yarn install doesn't think we need

yarn.lock

@@ -8042,22 +8042,6 @@ node-notifier@^5.4.2:
     shellwords "^0.1.1"
     which "^1.3.0"
 
-node-pre-gyp@*:
-  version "0.14.0"
-  resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.14.0.tgz#9a0596533b877289bcad4e143982ca3d904ddc83"
-  integrity sha512-+CvDC7ZttU/sSt9rFjix/P05iS43qHCOOGzcr3Ry99bXG7VX953+vFyEuph/tfqoYu8dttBkE86JSKBO2OzcxA==
-  dependencies:
-    detect-libc "^1.0.2"
-    mkdirp "^0.5.1"
-    needle "^2.2.1"
-    nopt "^4.0.1"
-    npm-packlist "^1.1.6"
-    npmlog "^4.0.2"
-    rc "^1.2.7"
-    rimraf "^2.6.1"
-    semver "^5.3.0"
-    tar "^4.4.2"
-
 node-pre-gyp@^0.11.0:
   version "0.11.0"
   resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.11.0.tgz#db1f33215272f692cd38f03238e3e9b47c5dd054"
@@ -11501,7 +11485,7 @@ tar-stream@^2.1.0:
     inherits "^2.0.3"
     readable-stream "^3.1.1"
 
-tar@^4, tar@^4.4.2:
+tar@^4:
   version "4.4.13"
   resolved "https://registry.yarnpkg.com/tar/-/tar-4.4.13.tgz#43b364bc52888d555298637b10d60790254ab525"
   integrity sha512-w2VwSrBoHa5BsSyH+KxEqeQBAllHhccyMFVHtGtdMpF4W7IRWfZjFiQceJPChOeTsSDVUpER2T8FA93pr0L+QA==