update travis config

.travis.yml

@@ -30,12 +30,12 @@ before_script:
 
 script:
   - |
-    if [[ "$TRAVIS_RUST_VERSION" != "stable" ]]; then
+    if [[ "$TRAVIS_RUST_VERSION" != "nightly" ]]; then
     cargo clean
     cargo test --features="ssl,tls,rust-tls" -- --nocapture
     fi
   - |
-    if [[ "$TRAVIS_RUST_VERSION" == "stable" ]]; then
+    if [[ "$TRAVIS_RUST_VERSION" == "nightly" ]]; then
     RUSTFLAGS="--cfg procmacro2_semver_exempt" cargo install -f cargo-tarpaulin
     cargo tarpaulin --features="ssl,tls,rust-tls" --out Xml --no-count
     bash <(curl -s https://codecov.io/bash)
@@ -45,7 +45,7 @@ script:
 # Upload docs
 after_success:
   - |
-    if [[ "$TRAVIS_OS_NAME" == "linux" && "$TRAVIS_PULL_REQUEST" = "false" && "$TRAVIS_BRANCH" == "master" && "$TRAVIS_RUST_VERSION" == "beta" ]]; then
+    if [[ "$TRAVIS_OS_NAME" == "linux" && "$TRAVIS_PULL_REQUEST" = "false" && "$TRAVIS_BRANCH" == "master" && "$TRAVIS_RUST_VERSION" == "stable" ]]; then
       cargo doc --features "ssl,tls,rust-tls,session" --no-deps &&
       echo "<meta http-equiv=refresh content=0;url=os_balloon/index.html>" > target/doc/index.html &&
       git clone https://github.com/davisp/ghp-import.git &&