Update installation.rst

Fix code block for software update.
Update installation.rst

Fix Geotrek directory name once unzipped in SOFTWARE UPDATE.
Merge pull request #1233 from camillemonchicourt/patch-2

Update installation.rst
Merge pull request #1234 from camillemonchicourt/patch-3

Update installation.rst
Missing pytz lib
Merge pull request #1239 from makinacorpus/missing_pytz

Missing pytz lib
Merge remote-tracking branch 'origin/develop'
Bump version