Merge snap code into the Certbot repo

* merge .gitignore

* Move snapcraft.yml up one level.

* update source

* move test.sh to tox.ini

* use new tox.ini in .travis.yml

* move snap build code

* make script executable

* remove unused python3-dev

* don't use deprecated classic flag

* go back to stable channel

* add nginx in snap addons

* add deploy steps

* Add comments explaining external tox envs.

* error if not in CI

* don't use --depth

* remove old .travis.yml

* Add big comment about SNAP_TOKEN.

* Set all_branches: true.

* Add repo setting.

* run travis on tags

* Add more documenting comments to .travis.yml.

snap/snapcraft.yaml

@@ -0,0 +1,88 @@
+name: certbot
+summary: Automatically configure HTTPS using Let's Encrypt
+description: |
+ The objective of Certbot, Let's Encrypt, and the ACME (Automated
+ Certificate Management Environment) protocol is to make it possible
+ to set up an HTTPS server and have it automatically obtain a
+ browser-trusted certificate, without any human intervention. This is
+ accomplished by running a certificate management agent on the web
+ server.
+ 
+ This agent is used to:
+   - Automatically prove to the Let's Encrypt CA that you control the website
+   - Obtain a browser-trusted certificate and set it up on your web server
+   - Keep track of when your certificate is going to expire, and renew it
+   - Help you revoke the certificate if that ever becomes necessary.
+confinement: classic
+grade: devel
+base: core18
+adopt-info: certbot
+
+apps:
+  certbot:
+    command: certbot
+    environment:
+      PATH: "$SNAP/bin:$SNAP/usr/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
+      AUGEAS_LENS_LIB: "$SNAP/usr/share/augeas/lenses/dist"
+      LD_LIBRARY_PATH: "$SNAP/usr/lib/x86_64-linux-gnu/:$LD_LIBRARY_PATH"
+  renew:
+    command: certbot -q renew
+    daemon: oneshot
+    environment:
+      PATH: "$SNAP/bin:$SNAP/usr/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
+      AUGEAS_LENS_LIB: $SNAP/usr/share/augeas/lenses/dist
+      LD_LIBRARY_PATH: "$SNAP/usr/lib/x86_64-linux-gnu/:$LD_LIBRARY_PATH"
+    passthrough:
+        # Run approximately twice a day with randomization
+        timer: 00:00~24:00/2
+
+parts:
+  python-augeas:
+    plugin: python
+    source: git://github.com/basak/python-augeas
+    source-branch: snap
+    python-version: python3
+    build-packages: [libaugeas-dev]
+  acme:
+    plugin: python
+    source: .
+    source-subdir: acme
+    constraints: [$SNAPCRAFT_PART_SRC/constraints.txt]
+    python-version: python3
+  certbot:
+    plugin: python
+    source: .
+    source-subdir: certbot
+    constraints: [$SNAPCRAFT_PART_SRC/constraints.txt]
+    python-version: python3
+    after: [acme]
+    override-pull: |
+        snapcraftctl pull
+        snapcraftctl set-version `cd $SNAPCRAFT_PART_SRC && git describe|sed s/^v//`
+    # Workaround for lack of site-packages leading to empty sitecustomize.py
+    stage:
+      - -usr/lib/python3.6/sitecustomize.py
+  certbot-apache:
+    plugin: python
+    source: .
+    source-subdir: certbot-apache
+    constraints: [$SNAPCRAFT_PART_SRC/constraints.txt]
+    python-version: python3
+    after: [python-augeas, certbot]
+    stage-packages: [libaugeas0]
+    stage:
+      # Prefer cffi
+      - -lib/python3.6/site-packages/augeas.py
+  certbot-nginx:
+    plugin: python
+    source: .
+    source-subdir: certbot-nginx
+    constraints: [$SNAPCRAFT_PART_SRC/constraints.txt]
+    python-version: python3
+    # This is the last step, compile pycache now as there should be no conflicts.
+    override-prime: |
+      snapcraftctl prime
+      ./usr/bin/python3 -m compileall -q .
+    # After certbot-apache to not rebuild duplicates (essentially sharing what was already staged,
+    # like zope)
+    after: [certbot-apache]