feat: improves coverage of the $project specs (#43)

* feat: allow suppression of _id field on $project stage (#37)

https://www.mongodb.com/docs/manual/reference/operator/aggregation/project/#suppress-the-_id-field

* fix: includes _id when it's omitted altogether from $project stage

* feat: supports $literal on $project stage (#37)

* feat: simple field renames on $project stage

* feat: renaming nested and flat fields on $project stage (#37)

* feat: handle arrays on $project stage (#37)

* docs: bumped README info to reflect 0.1.4 changes

README.md

@@ -97,19 +97,26 @@ By default oxide will bind to 127.0.0.1 and port 27017. You can change those set
 
 ```
 > $ ./oxide --help
-oxide 0.1.3
+oxide 0.1.4
 A database compatible with MongoDB Wire Protocol that uses PostgreSQL for backend storage.
 
 USAGE:
     oxide [OPTIONS]
+    oxide <SUBCOMMAND>
 
 OPTIONS:
     -d, --debug                          Show debugging information
     -h, --help                           Print help information
-    -l, --listen-addr <LISTEN_ADDR>      Listening address defaults to 127.0.0.1
+    -l, --listen-addr <LISTEN_ADDR>      Listening address, defaults to 127.0.0.1
     -p, --port <PORT>                    Listening port, defaults to 27017
     -u, --postgres-url <POSTGRES_URL>    PostgreSQL connection URL
     -V, --version                        Print version information
+    -w, --web                            Starts web interface
+        --web-addr <WEB_ADDR>            Web binding address
+
+SUBCOMMANDS:
+    help    Print this message or the help of the given subcommand(s)
+    web     Start OxideDB web interface
 ```
 
 ### Running with Docker