In a multi-module repository, the top-level LICENSE file is used for
all modules in the repository. However, when using a "replace" rule,
the vendored file is removed, but added back when removing the replace
rule.
This patch adds copies of the license to each of the modules to reduce
code-churn; these are vanilla copies downloaded from;
https://www.apache.org/licenses/LICENSE-2.0.txt
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
