Delete .travis.yml (#168)

.travis.yml

@@ -1,24 +0,0 @@
-sudo: required
-dist: bionic
-
-language: csharp
-mono: none
-dotnet: 2.0.0
-solution: DepotDownloader.sln
-
-install:
-    - dotnet restore DepotDownloader.sln
-
-script:
-    - dotnet build DepotDownloader.sln
-
-notifications:
-    irc:
-        channels:
-            - "irc.gamesurge.net#opensteamworks"
-        on_success: never
-        on_failure: always
-
-cache:
-    directories:
-        - "~/.local/share/NuGet/Cache"