get rid of coverity as it is not useful for Python

.travis.yml

@@ -1,24 +1,13 @@
 language: python
 python:
 - '3.4'
+- '3.6'
 - '3.7'
 env:
   global:
   - secure: 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
 install:
-- pip install -r requirements.txt
-addons:
-  coverity_scan:
-    # customized build script URL
-    # TRAVIS_REPO_SLUG: owner_name/repo_name of repository currently being built
-    # TRAVIS_BRANCH: name of the branch currently being built
-    build_script_url: https://raw.githubusercontent.com/KissPeter/APIFuzzer/master/.travis-coverity-scan-build.sh
-    # project metadata
-    project:
-      name: KissPeter/APIFuzzer
-    notification_email: kiss.peter@linuxadm.hu
-    branch_pattern: master
-
+- pip3 install -r requirements.txt
 script:
 - python fuzzer.py -h
 - pip3 install -r test/requirements_for_test.txt