CI: Only needed dependencies for GetReleaseVersion

Saves a few seconds per run.

Author: DeeDeeG

script/vsts/nightly-release.yml

@@ -7,7 +7,7 @@ jobs:
       # exits the script block after `npm install` completes.
       - script: |
           cd script/vsts
-          npm install
+          npm install request-promise-native yargs
         displayName: npm install
       - script: node script/vsts/get-release-version.js --nightly
         name: Version

script/vsts/pull-requests.yml

@@ -9,7 +9,7 @@ jobs:
       # exits the script block after `npm install` completes.
       - script: |
           cd script/vsts
-          npm install
+          npm install request-promise-native yargs
         displayName: npm install
       - script: node script/vsts/get-release-version.js
         name: Version

script/vsts/release-branch-build.yml

@@ -13,7 +13,7 @@ jobs:
       # exits the script block after `npm install` completes.
       - script: |
           cd script/vsts
-          npm install
+          npm install request-promise-native yargs
         displayName: npm install
       - script: node script/vsts/get-release-version.js
         name: Version