Restore optionaldeps and remove webworker dependency during build

Author: Rik Smith-Unna

.appveyor.yml

@@ -10,7 +10,7 @@ init:
 
 install:
   - ps: Install-Product node 8 x64
-  - yarn && cd app && yarn --ignore-optional && yarn run rebuildwin && cd ..
+  - yarn && cd app && yarn && yarn run rebuildwin && cd ..
   - rm -rf app/node_modules/webworker-threads
 
 build_script:

.travis.yml

@@ -37,7 +37,8 @@ before_install:
 install:
   - yarn
   - yarn add electron-builder@next --dev # force install next version to test electron-builder
-  - cd app && yarn --ignore-optional && cd ..
+  - cd app && yarn && cd ..
+  - rm -rf ./app/node_modules/webworker-threads
 
 script:
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then yarn run buildosx ; fi