Upgrade tested version to something more recent

The versions used in the test were very old,
and none of them would work on a recent OSX machine.
Due to the age of such release, they could also confuse new contributors
as many bugfixes / features were missing.

test/t/base.sh

@@ -3,30 +3,30 @@
 set -uexo pipefail
 
 compilers=(
- dmd-2.064
- dmd-2.069.2
- dmd-2.071.2
- dmd-2.077.1
- dmd-master-2018-10-14
- ldc-1.4.0
+ dmd-2.094
+ dmd-2.089.2
+ dmd-2.091.2
+ dmd-2.087.1
+ dmd-master-2020-05-10
+ ldc-1.24.0
 )
 
 versions=(
  'DMD64 D Compiler v2.064'
  'DMD64 D Compiler v2.069.2'
  'DMD64 D Compiler v2.071.2'
  'DMD64 D Compiler v2.077.1'
- 'DMD64 D Compiler v2.082.1-master-54b676b'
- 'LDC - the LLVM D compiler (1.4.0):'
+ 'DMD64 D Compiler v2.090.0-beta.1-master-49dfbe5'
+ 'LDC - the LLVM D compiler (1.24.0):'
 )
 
 frontendVersions=(
- '2064'
- '2069'
- '2071'
- '2077'
- '2082'
- '2074'
+ '2094'
+ '2089'
+ '2091'
+ '2087'
+ '2090'
+ '2094'
 )
 
 if [ "${TRAVIS_OS_NAME:-}" = "linux" ]; then