tests/test-encode.out

tests: fix bashism to load helpers.sh

`source` isn't available at POSIX sh.

%% no changes
%% no changes
%% check contents in repo are encoded
this is a test
THIS IS A TEST
%% check committed content was decoded
this is a test
this is a test
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
%% check decoding of our new working dir copy
this is a test
this is a test
%% check hg cat operation
this is a test
this is a test
this is a test
this is a test