Remove Appveyor (#264)

Now that we have azure pipelines set up, there is no need
to use appveyor.

Part of https://github.com/graphql-rust/juniper/issues/259

README.md

@@ -3,7 +3,6 @@
 > GraphQL server library for Rust
 
 [![Build Status](https://travis-ci.org/graphql-rust/juniper.svg?branch=master)](https://travis-ci.org/graphql-rust/juniper)
-[![Build status](https://ci.appveyor.com/api/projects/status/xav6tor6biu617uu?svg=true)](https://ci.appveyor.com/project/theduke/juniper)
 [![Build Status](https://dev.azure.com/graphql-rust/GraphQL%20Rust/_apis/build/status/graphql-rust.juniper)](https://dev.azure.com/graphql-rust/GraphQL%20Rust/_build/latest?definitionId=1)
 [![codecov](https://codecov.io/gh/graphql-rust/juniper/branch/master/graph/badge.svg)](https://codecov.io/gh/graphql-rust/juniper)
 [![Crates.io](https://img.shields.io/crates/v/juniper.svg?maxAge=2592000)](https://crates.io/crates/juniper)

appveyor.yml

@@ -1,41 +0,0 @@
-# Build and test on stable, beta, and nightly on Windows.
-#
-# Copied general structure from https://github.com/japaric/rust-everywhere/blob/master/appveyor.yml
-
-environment:
-  matrix:
-    # Stable channel
-    - TARGET: x86_64-pc-windows-gnu
-      CHANNEL: stable
-    - TARGET: x86_64-pc-windows-msvc
-      CHANNEL: stable
-    # Beta channel
-    - TARGET: x86_64-pc-windows-gnu
-      CHANNEL: beta
-    - TARGET: x86_64-pc-windows-msvc
-      CHANNEL: beta
-    # Nightly channel
-    - TARGET: x86_64-pc-windows-gnu
-      CHANNEL: nightly
-    - TARGET: x86_64-pc-windows-msvc
-      CHANNEL: nightly
-
-# Install Rust ,Cargo and cargo-make.
-# (Based on from https://github.com/rust-lang/libc/blob/master/appveyor.yml)
-install:
-  - curl -sSf -o rustup-init.exe https://win.rustup.rs
-  - rustup-init.exe --default-host %TARGET% --default-toolchain %CHANNEL% -y
-  - set PATH=%PATH%;C:\Users\appveyor\.cargo\bin
-  - rustc -Vv
-  - cargo -V
-  - cargo install --debug cargo-make
-
-
-# 'cargo test' takes care of building for us, so disable Appveyor's build stage. This prevents
-# the "directory does not contain a project or solution file" error.
-# source: https://github.com/starkat99/appveyor-rust/blob/master/appveyor.yml#L113
-build: false
-
-test_script:
-   - cargo make workspace-ci-flow --no-workspace
-

juniper/Cargo.toml

@@ -15,7 +15,6 @@ categories = ["web-programming"]
 
 [badges]
 travis-ci = { repository = "graphql-rust/juniper" }
-appveyor = { repository = "graphql-rust/juniper" }
 
 [[bench]]
 name = "bench"

juniper_codegen/Cargo.toml

@@ -22,4 +22,3 @@ lazy_static = "1.0.0"
 
 [badges]
 travis-ci = { repository = "graphql-rust/juniper" }
-appveyor = { repository = "graphql-rust/juniper" }