Fix typos discovered by codespell (#1496)

# https://pypi.org/project/codespell
% `codespell`
```
./emsdk.py:1459: thier ==> their
./test/test.bat:1: equivilent ==> equivalent
./test/test.py:198: Specificlly ==> Specifically
./scripts/update_bazel_workspace.py:2: revisons ==> revisions
./scripts/update_node.py:11: direcotry ==> directory
./bazel/emscripten_toolchain/BUILD.bazel:57: implictly ==> implicitly
./docker/Dockerfile:87: terninal ==> terminal
```

docker/Dockerfile

@@ -84,7 +84,7 @@ RUN echo "## Update and install packages" \
     && apt-get -qq -y update \
     # Somewhere in here apt sets up tzdata which asks for your time zone and blocks
     # waiting for the answer which you can't give as docker build doesn't read from
-    # the terninal. The env vars set here avoid the interactive prompt and set the TZ.
+    # the terminal. The env vars set here avoid the interactive prompt and set the TZ.
     && DEBIAN_FRONTEND="noninteractive" TZ="America/San_Francisco" apt-get -qq install -y --no-install-recommends \
         sudo \
         libxml2 \