AppVeyor workaround for TMP issue, also add timeout

See https://github.com/quasicomputational/hpack/commit/ce868d17e53289eab3703261a5a3dc8d48364533,
and https://github.com/commercialhaskell/stack/issues/3944

.travis.yml

@@ -1,3 +1,10 @@
+## Travis is used for building an OSX binary on new tag releases,
+## it also compiles the project on OSX for each commit to master.
+##
+## Building the whole project can take longer than 50 minutes. Since Travis has a global timeout of 50 minutes
+## we compile for 30 minutes tops(see `gtimeout 1800` below) and quit compiling with no error.
+## Since we CACHE the compile results we can continue compiling from where we left off
+## on the next commit.
 language: generic
 
 sudo: false

appveyor.yml

@@ -1,3 +1,4 @@
+## AppVeyor is used for building a Windows binary on new tag releases
 platform: x64
 
 cache:
@@ -8,6 +9,7 @@ environment:
   global:
     STACK_ROOT: "c:\\sr"
     GOPATH: c:\gopath
+    TMP: "c:\\tmp"
 
 test: off
 
@@ -28,7 +30,7 @@ install:
 
 build_script:
 - stack setup --no-terminal > nul
-- stack build -j1 --copy-bins --local-bin-path .
+- bash -lc "timeout 2700 'C:\projects\postgrest\stack.exe' build -j1 --copy-bins --local-bin-path . || true"
 
 artifacts:
 - path: postgrest.exe