Misc. typos

Found via `codespell -q 3 -I ../mitmproxy-word-whitelist.txt`
Where whitelist contains:
```
cas
doubleclick
nd
ot
seeked
statics
te
thru
```

1 files changed, 1 insertions, 1 deletions

diff --git a/mitmproxy/test/taddons.py b/mitmproxy/test/taddons.py
index 5930e414..1ca8ba8d 100644
--- a/mitmproxy/test/taddons.py
+++ b/mitmproxy/test/taddons.py
@@ -137,7 +137,7 @@ class context:
 
     def command(self, func, *args):
         """
-            Invoke a command function with a list of string arguments within a command context, mimicing the actual command environment.
+            Invoke a command function with a list of string arguments within a command context, mimicking the actual command environment.
         """
         cmd = command.Command(self.master.commands, "test.command", func)
         return cmd.call(args)