Generate snapcraft.yml on the fly to contain correct version

.gitignore

@@ -67,3 +67,4 @@ client_secret.json
 /logfile.txt
 /app/dist-docs
 /app/mailsync.dSYM.zip
+/snap/snapcraft.yml

.travis.yml

@@ -93,6 +93,9 @@ cache:
   - /tmp/mailsync-build-deps
 
 after_success:
+# Grab the version number from the .deb product and update the snapcraft.yml file
+- sed "s/MAILSPRING_VERSION/$(grep -E -o '([0-9]+.[0-9]+.[0-9]+)' <<< "$(find app/dist -type f -name mailspring-*.deb)")/g" snap/snapcraft.template.yaml > snap/snapcraft.yml
+# Decrypt the snapcraft login information
 - openssl aes-256-cbc -K $encrypted_f8421d18d2b7_key -iv $encrypted_f8421d18d2b7_iv
   -in .snapcraft/travis_snapcraft.cfg -out .snapcraft/snapcraft.cfg -d
 
@@ -103,5 +106,5 @@ deploy:
   'on':
     branch: master
   provider: script
-  script: docker run --env MAILSPRING_VERSION="$(grep -E -o '([0-9]+.[0-9]+.[0-9]+)' <<< "$(find app/dist -type f -name mailspring-*.deb)")" -v $(pwd):$(pwd) -t snapcore/snapcraft sh -c "apt update -qq && cd $(pwd) && snapcraft && snapcraft push *.snap --release edge"
+  script: docker run -v $(pwd):$(pwd) -t snapcore/snapcraft sh -c "apt update -qq && cd $(pwd) && snapcraft && snapcraft push *.snap --release edge"
   skip_cleanup: true

snap/snapcraft.template.yaml

@@ -1,5 +1,5 @@
 name: mailspring
-version: $MAILSPRING_VERSION
+version: MAILSPRING_VERSION
 summary: The best email app for people and teams at work
 description: |
  An extensible desktop mail app built on the modern web.
@@ -9,7 +9,7 @@ confinement: strict
 parts:
   mailspring:
     plugin: dump
-    source: ./app/dist/mailspring-$MAILSPRING_VERSION-amd64.deb
+    source: ./app/dist/mailspring-MAILSPRING_VERSION-amd64.deb
     source-type: deb
     # Correct path to icon.
     prepare: |