Rename stubs to .pyi and reformat them

stubs/gnupg.py → stubs/gnupg.pyi

@@ -1,23 +1,15 @@
 from typing import List, Optional
 
-
 class ImportResult:
     stderr: str
     fingerprints: List[str]
     sec_imported: int
 
-
 class Sign:
     stderr: str
     status: Optional[str]
 
-
 class GPG:
-    def __init__(self, *, gnupghome: str, use_agent: bool) -> None:
-        ...
-
-    def import_keys(self, data: str) -> ImportResult:
-        ...
-
-    def sign(self, data: str, passphrase: Optional[str]) -> Sign:
-        ...
+    def __init__(self, *, gnupghome: str, use_agent: bool) -> None: ...
+    def import_keys(self, data: str) -> ImportResult: ...
+    def sign(self, data: str, passphrase: Optional[str]) -> Sign: ...

stubs/pexpect.pyi

@@ -0,0 +1,5 @@
+class Spawn:
+    def expect(self, expected: str) -> int: ...
+    def sendline(self, line: str) -> int: ...
+
+def spawn(cmd: str) -> Spawn: ...

stubs/semver.pyi

@@ -0,0 +1,8 @@
+from __future__ import annotations
+
+class VersionInfo:
+    prerelease: str
+    build: str
+    def __lt__(self, other: VersionInfo) -> bool: ...
+
+def parse_version_info(version: str) -> VersionInfo: ...