Upgrade spdlog to 1.10.0 (rapidsai#312)

Upgrades the default spdlog version to 1.10.0 to match the conda-forge pinning.

Authors:
  - Keith Kraus (https://github.com/kkraus14)

Approvers:
  - Robert Maynard (https://github.com/robertmaynard)

URL: rapidsai#312

rapids-cmake/cpm/versions.json

@@ -32,7 +32,7 @@
       "git_tag" : "branch-${version}"
     },
     "spdlog" : {
-      "version" : "1.8.5",
+      "version" : "1.10.0",
       "git_url" : "https://github.com/gabime/spdlog.git",
       "git_tag" : "v${version}"
     },