Use a fork of boto without FileChunkIO requirement

See https://github.com/boto/boto/pull/2704.
2017-10-02 09:39:01 +09:00 · 2017-10-02 09:39:01 +09:00 · 47a0a8a887
--- a/.gitmodules
+++ b/.gitmodules
@ -3,4 +3,4 @@
 	url = https://chromium.googlesource.com/chromium/tools/depot_tools.git
 [submodule "vendor/boto"]
 	path = vendor/boto
-	url = https://github.com/boto/boto
+	url = https://github.com/piotrbulinski/boto.git
--- a/vendor/boto
+++ b/vendor/boto
@ -1 +1 @@
-Subproject commit f7574aa6cc2c819430c1f05e9a1a1a666ef8169b
+Subproject commit c3b81eb115e469b9df1ff8c379d3208327da2c84