Add OTP-27 to CI workflow

Bumps workflow to OTP versions 25-27.
The rebar3 bootstrap reqires at least OTP-25, so rather that checkout earier tags for each older
version of OTP we will just check against the most recent 3 versions.

Signed-off-by: Winford <[email protected]>

Author: UncleGrumpy

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

@@ -13,7 +13,7 @@ jobs:
     runs-on: "ubuntu-20.04"
     strategy:
       matrix:
-        otp: ["24", "25", "26"]
+        otp: ["25", "26", "27"]
 
     steps:
     # Setup