Require HHVM 4.93 (#169)

Summary:
Needed for coeffect/capability syntax

Pull Request resolved: #169

Reviewed By: jjergus

Differential Revision: D25961865

Pulled By: fredemmott

fbshipit-source-id: 59d0c25847c84bc6acd2aad51f43c6c76fda93b7

Author: fredemmott

.github/workflows/build-and-test.yml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         os: [ ubuntu , macos ]
         hhvm:
-          - 4.76
+          - 4.93
           - latest
           - nightly
     runs-on: ${{matrix.os}}-latest

composer.json

@@ -13,7 +13,7 @@
     "hhvm/hhvm-autoload": "^2.0|^3.0"
   },
   "require": {
-    "hhvm": "^4.76",
+    "hhvm": "^4.93",
     "hhvm/hsl": "^4.15"
   },
   "provide": {