Test against Webpack 5

Author: jscheid

.travis.yml

@@ -13,7 +13,7 @@ env:
   - WEBPACK_SUFFIX="@3" ETWP_SUFFIX="@3" HWP_SUFFIX="@2"
   - WEBPACK_SUFFIX="@4" ETWP_SUFFIX="@4.0.0-alpha.0" HWP_SUFFIX="@3"
   - WEBPACK_SUFFIX="@4" ETWP_SUFFIX="@4.0.0-alpha.0" HWP_SUFFIX="@4"
-  - WEBPACK_SUFFIX="@next" ETWP_SUFFIX="@4.0.0-alpha.0" HWP_SUFFIX="@4"
+  - WEBPACK_SUFFIX="@5" ETWP_SUFFIX="@4.0.0-alpha.0" HWP_SUFFIX="@4"
 matrix:
   exclude:
   - node_js: 4

appveyor.yml

@@ -77,7 +77,7 @@ environment:
       FL_SUFFIX: '@1'
       HWP_SUFFIX: '@4'
     - nodejs_version: 10
-      WEBPACK_SUFFIX: '@next'
+      WEBPACK_SUFFIX: '@5'
       ETWP_SUFFIX: '@4.0.0-alpha.0'
       FL_SUFFIX: '@1'
       HWP_SUFFIX: '@4'
@@ -107,7 +107,7 @@ environment:
       FL_SUFFIX: '@1'
       HWP_SUFFIX: '@4'
     - nodejs_version: 12
-      WEBPACK_SUFFIX: '@next'
+      WEBPACK_SUFFIX: '@5'
       ETWP_SUFFIX: '@4.0.0-alpha.0'
       FL_SUFFIX: '@1'
       HWP_SUFFIX: '@4'