fix: install semantic-release as a regular dev dependency (#3455)

Also changed global executable to NPM script as global executable will not be available unless the package is installed globally (with `npm i -g`).

Author: devoto13

.travis.yml

@@ -49,6 +49,5 @@ after_success:
   # run automated release process with semantic-release
   - echo "TRAVIS_BRANCH=$TRAVIS_BRANCH, TRAVIS_EVENT_TYPE=$TRAVIS_EVENT_TYPE, TRAVIS_NODE_VERSION=$TRAVIS_NODE_VERSION"
   - if [[ "$TRAVIS_BRANCH" == "master" && "$TRAVIS_EVENT_TYPE" == "push" && "$TRAVIS_NODE_VERSION" == "12" ]]; then
-      npm i --no-save semantic-release@15 @semantic-release/changelog@3 @semantic-release/git@7;
-      semantic-release;
-    fi;
+      npm run semantic-release;
+    fi;