3057 Replacing 'master' to 'HEAD' for default git commit

core/dbt/clients/git.py

@@ -52,7 +52,7 @@ def _checkout(cwd, repo, branch):
 
 def checkout(cwd, repo, branch=None):
     if branch is None:
-        branch = 'master'
+        branch = 'HEAD'
     try:
         return _checkout(cwd, repo, branch)
     except dbt.exceptions.CommandResultError as exc:

core/dbt/deps/git.py

@@ -72,7 +72,7 @@ def _checkout(self):
 
     def _fetch_metadata(self, project, renderer) -> ProjectPackageMetadata:
         path = self._checkout()
-        if self.revision == 'master' and self.warn_unpinned:
+        if self.revision == 'HEAD' and self.warn_unpinned:
             warn_or_error(
                 'The git package "{}" is not pinned.\n\tThis can introduce '
                 'breaking changes into your project without warning!\n\nSee {}'
@@ -133,7 +133,7 @@ def incorporate(
     def resolved(self) -> GitPinnedPackage:
         requested = set(self.revisions)
         if len(requested) == 0:
-            requested = {'master'}
+            requested = {'HEAD'}
         elif len(requested) > 1:
             raise_dependency_error(
                 'git dependencies should contain exactly one version. '

test/unit/test_deps.py

@@ -104,7 +104,7 @@ def test_default_revision(self):
 
         a_pinned = a.resolved()
         self.assertEqual(a_pinned.name, 'http://example.com')
-        self.assertEqual(a_pinned.get_version(), 'master')
+        self.assertEqual(a_pinned.get_version(), 'HEAD')
         self.assertEqual(a_pinned.source_type(), 'git')
         self.assertIs(a_pinned.warn_unpinned, True)