switch oauth_dropins symlink to oauth_dropins_static, drop it from repo

it's now local clone only. this avoids import confusion, ie whether importing oauth_dropins uses the virtualenv's installed version or the symlinked files directly, which eg ran oauth-dropins's tests along with granary's/bridgy's, and caused Circle breakages like https://app.circleci.com/pipelines/github/snarfed/granary/767/workflows/21608f75-bb99-47dc-83ef-78d4f4793ed1/jobs/2819

    corresponds to snarfed/granary@00294822d6, snarfed/bridgy@b3f50d8248

README.md

@@ -57,7 +57,7 @@ TweepError: must be _socket.socket, not socket
 error: option --home not recognized
 ```
 
-You may need to change [granary](https://github.com/snarfed/granary), [oauth-dropins](https://github.com/snarfed/oauth-dropins), [webmention-tools](https://github.com/snarfed/webmention-tools), [mf2util](https://github.com/kylewm/mf2util), or other dependencies as well as as Bridgy Fed. To do that, clone their repo locally, then install them in "source" mode with e.g.:
+You may need to change [granary](https://github.com/snarfed/granary), [oauth-dropins](https://github.com/snarfed/oauth-dropins), [mf2util](https://github.com/kylewm/mf2util), or other dependencies as well as as Bridgy Fed. To do that, clone their repo locally, then install them in "source" mode with e.g.:
 
 ```sh
 pip uninstall -y granary

app.yaml

@@ -21,22 +21,12 @@ automatic_scaling:
 handlers:
 
 # static
-- url: /(static/bootstrap.*\.css)
-  static_files: oauth_dropins/\1
-  upload: oauth_dropins/static/bootstrap.*\.css
-  secure: always
-
 - url: /static
   static_dir: static
   secure: always
 
-- url: /oauth_dropins/static
-  static_dir: oauth_dropins/static
-  secure: always
-
-- url: /.well-known/acme-challenge
-  static_dir: .well-known/acme-challenge
-  secure: always
+- url: /oauth_dropins_static
+  static_dir: oauth_dropins_static
 
 - url: /
   static_files: static/index.html

oauth_dropins

@@ -1 +0,0 @@
-../oauth-dropins/oauth_dropins

oauth_dropins_static

@@ -0,0 +1 @@
+../oauth-dropins/oauth_dropins/static

static/index.html

@@ -10,7 +10,7 @@
 <!-- 32x32 last so that browsers prefer it -->
 <link rel="shortcut icon" sizes="32x32" href="https://brid.gy/static/favicon.png">
 <link rel="apple-touch-icon-precomposed" sizes="32x32" href="https://brid.gy/static/favicon.png">
-<link rel="stylesheet" href="/static/bootstrap.min.css" />
+<link rel="stylesheet" href="/oauth_dropins_static/bootstrap.min.css" />
 <link rel="stylesheet" href="/static/style.css" type="text/css" />
 <link rel="webmention" href="/webmention" />
 </head>

templates/responses.html

@@ -5,7 +5,7 @@
 <title>Bridgy Fed: Logs</title>
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <meta name="mobile-web-app-capable" content="yes"/>
-<link rel="stylesheet" href="/static/bootstrap.min.css" />
+<link rel="stylesheet" href="/oauth_dropins_static/bootstrap.min.css" />
 <link rel="stylesheet" href="/static/style.css" type="text/css" />
 </head>