use subdir to be consistent with existing package key

Author: simonbyrne

src/register.jl

@@ -343,7 +343,7 @@ function update_versions_file(pkg::Project,
         version_info["git-tag-name"] = tag_name
     end
     if subdir != ""
-        version_info["git-tree-path"] = subdir
+        version_info["subdir"] = subdir
     end
     versions_data[string(pkg.version)] = version_info
 
@@ -364,7 +364,7 @@ function update_versions_file(pkg::Project,
                     return 3
                 elseif x == "git-tag-name"
                     return 4
-                elseif x == "git-tree-path"
+                elseif x == "subdir"
                     return 5
                 elseif x == "yanked"
                     return 100

test/regedit.jl

@@ -304,10 +304,10 @@ end
         @test data isa Dict
         @test collect(keys(data)) == ["1.0.0"]
         @test data["1.0.0"] isa Dict
-        @test sort!(collect(keys(data["1.0.0"]))) == ["git-commit-sha1", "git-tree-path", "git-tree-sha1"]
+        @test sort!(collect(keys(data["1.0.0"]))) == ["git-commit-sha1", "git-tree-sha1", "subdir"]
         @test data["1.0.0"]["git-tree-sha1"] == tree_hash
         @test data["1.0.0"]["git-commit-sha1"] == commit_hash
-        @test data["1.0.0"]["git-tree-path"] == subdir
+        @test data["1.0.0"]["subdir"] == subdir
 
         check_versions!(pkg, data, status)
         # This version was just registered, should be a complaint now.