Shellcheck ci scripts, add a small .editorconfig (#186)

* Shellcheck ci/script.sh

* Shellcheck ci/install.sh, simplify script a bit

* Add .editorconfig for ci/*.sh

* Shellcheck ci/before_deploy.sh

ci/before_deploy.sh

@@ -3,10 +3,9 @@
 set -ex
 
 main() {
-    local src=$(pwd) \
-          stage=
+    src=$(pwd)
 
-    case $TRAVIS_OS_NAME in
+    case "$TRAVIS_OS_NAME" in
         linux)
             stage=$(mktemp -d)
             ;;
@@ -18,16 +17,16 @@ main() {
     test -f Cargo.lock || cargo generate-lockfile
 
     # TODO Update this to build the artifacts that matter to you
-    cross rustc --bin topgrade --target $TARGET --release --all-features -- -C lto
+    cross rustc --bin topgrade --target "$TARGET" --release --all-features -- -C lto
 
     # TODO Update this to package the right artifacts
-    cp target/$TARGET/release/topgrade $stage/
+    cp target/"$TARGET"/release/topgrade "$stage"/
 
-    cd $stage
-    tar czf $src/$CRATE_NAME-$TRAVIS_TAG-$TARGET.tar.gz *
-    cd $src
+    cd "$stage"
+    tar czf "$src"/"$CRATE_NAME"-"$TRAVIS_TAG"-"$TARGET".tar.gz ./*
+    cd "$src"
 
-    rm -rf $stage
+    rm -rf "$stage"
 }
 
 main