arrow

ARROW-2894: [Glib] Adjust tests to format refactor

cc @kou

I I adjusted the tests to pass. Sadly I had to realise that some of the outputs still don't look pretty. I will change this in a follow-up PR.

There were some issues for me to build Glib in the same environment as the conda one described in https://arrow.apache.org/docs/python/development.html#developing-on-linux-and-macos.

- my configure command was
```
./configure PKG_CONFIG_PATH=$(brew --prefix libffi)/lib/pkgconfig:$CONDA_PREFIX/lib/pkgconfig/:$PKG_CONFIG_PATH --prefix=`pwd`/dist
```
- I had to run `cp $CONDA_PREFIX/lib/libarrow* arrow-glib/.libs/` as otherwise the GISCAN step would not suceed. Even setting `LD_LIBRARY_PATH` did not help
- To run the tests I also needed to add `GI.prepend_typelib_path('dist/lib/girepository-1.0/')` to `c_glib/test/run-test.rb`. Otherwise `GI.load("Arrow")` did not find the necessary definitions.

Author: Kouhei Sutou <kou@clear-code.com>
Author: Korn, Uwe <Uwe.Korn@blue-yonder.com>

Closes #2303 from xhochy/ARROW-2894 and squashes the following commits:

2eddda84 [Kouhei Sutou] [Ruby] Adjust tests to format refactor
edd7c208 [Kouhei Sutou] [GLib] Use here document for multi-line text
492f475a [Korn, Uwe] ARROW-2894: [Glib] Adjust tests to format refactor