Add ignores, fix dep caching self purging

.dockerignore

@@ -0,0 +1,10 @@
+### Rust template
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+.idea/

.gitignore

@@ -1,2 +1,3 @@
 /target
 .idea
+.env

Dockerfile

@@ -11,7 +11,7 @@ RUN cargo build --release
 # Build web app with own code
 RUN rm src/*.rs
 ADD . ./
-RUN rm ./target/release/deps/time-banner*
+RUN rm ./target/release/deps/time_banner*
 RUN cargo build --release