Update gitignore

Allow .dockerignore and .travis.yml

.dockerignore

@@ -0,0 +1,22 @@
+# Logs
+logs
+
+# Tests
+tests
+
+# Examples
+examples
+
+# Docs
+docs
+
+# Certs
+certs
+
+.coverage
+
+# Markdown
+*.md
+
+# Other
+*.yml

.gitignore

@@ -7,6 +7,8 @@ __pycache__
 # Except .
 !.github/
 !.gitignore
+!.dockerignore
+!.travis.yml
 
 # Ignore items in test (report, cache, etc), except files starting with test
 tests/*