Merge pull request #207 from julianpistorius/fix-broken-links

Problem: A few broken links

Author: kimberlyh66

index.Rmd

@@ -39,7 +39,7 @@ At a minimum, you should have:
 
 The first few chapters in the 'vignettes' section use publicly available sample data sets.
 Subsequent sections are also written to use publicly available data sets, but some of the examples require data that requires users to sign up.
-To sign up, you will need to 1) fill out the TERRA REF Beta user questionaire ([terraref.org/beta](terraref.org/beta)) and 2) request access to specific databases.
+To sign up, you will need to 1) fill out the TERRA REF Beta user questionaire ([terraref.org/beta](https://terraref.org/beta)) and 2) request access to specific databases.
 
 <!-- Not sure where this goes, either in documentation or perhaps in an appendix. But I don't think this belongs in the introduction. Perhaps after the vignettes chaper 
 -->
@@ -61,7 +61,7 @@ To sign up, you will need to 1) fill out the TERRA REF Beta user questionaire ([
 
 The TERRA REF website: [terraref.org](http://terraref.org/)
 
-The TERRA REF Technical Documentation: [docs.terraref.org](docs.terraref.org)
+The TERRA REF Technical Documentation: [docs.terraref.org](https://docs.terraref.org)
 
 
 ### Finding help

sensors/06-list-datasets-by-plot.Rmd

@@ -2,8 +2,8 @@
 
 ## Pre-requisites: 
 
-* if you have not already done so, you will need to 1) sign up for the [beta user program](terraref.org/beta) and 2) 
-sign up and be approved for access to the the [sensor data portal](terraref.ncsa.illinois.edu/clowder) in order to get 
+* if you have not already done so, you will need to 1) sign up for the [beta user program](https://terraref.org/beta) and 2)
+sign up and be approved for access to the the [sensor data portal](https://terraref.ncsa.illinois.edu/clowder) in order to get
 the API key that will be used in this tutorial. 
 
 The terrautils python package has a new `products` module that aids in connecting

vignettes/02-get-weather-data-R.Rmd

@@ -4,7 +4,7 @@
 
 This vignette shows how to read weather data for the month of January 2017 from the [weather station](https://cals-mac.arizona.edu/weather-station) at the University of Arizona's [Maricopa Agricultural Center](http://cals-mac.arizona.edu/) into R. 
 These data are stored online on the data management system Clowder, which is accessed using an API. 
-More detailed information about the structure of the database and how API URLs are created is available in the [weather tutorial]("sensors/01-meteorological-data.Rmd"). 
+More detailed information about the structure of the database and how API URLs are created is available in the [weather tutorial](sensors/01-meteorological-data.Rmd).
 Data across time for one weather variable, temperature, is plotted in R. 
 Then all eight of the weather variables have their times series plotted.