Update flake8 and fix warnings in .py files (#334)

.gitignore

@@ -1,30 +1,35 @@
-clang
-emscripten
-emsdk_set_env.bat
-emsdk_set_env.sh
-git
-node
-python
-temp
-zips
-crunch
-java
-mingw
-spidermonkey
-binaryen
-.emscripten
-.emscripten_cache
-.emscripten_cache__last_clear
-.emscripten_sanity
-.tmp
-tmp
-gnu
-emscripten-nightlies.txt
-llvm-nightlies-32bit.txt
-llvm-nightlies-64bit.txt
-llvm-tags-32bit.txt
-llvm-tags-64bit.txt
-upstream
-emscripten-releases-tot.txt
-fastcomp
-releases
+# Support for --embedded configs
+/.emscripten
+/.emscripten_cache
+/.emscripten_cache__last_clear
+/.emscripten_sanity
+
+# Auto-generated by `active`
+/emsdk_set_env.bat
+/emsdk_set_env.sh
+
+# Tags files that get generated at runtime
+/emscripten-nightlies.txt
+/llvm-nightlies-32bit.txt
+/llvm-nightlies-64bit.txt
+/llvm-tags-32bit.txt
+/llvm-tags-64bit.txt
+/emscripten-releases-tot.txt
+
+# File that get download/extracted by emsdk itself
+/gnu
+/upstream
+/fastcomp
+/releases
+/clang
+/emscripten
+/git
+/node
+/python
+/temp
+/zips
+/crunch
+/java
+/mingw
+/spidermonkey
+/binaryen