Release v0.7.0

Since 0.6.0 we fixed the following issues:

• #122 (closed): Remove public 'fname' learner attribute
• #119 (closed): (Learner1D) add possibility to use the direct neighbors in the loss
• #114 (closed): (LearnerND) allow any convex hull as domain
• #121 (closed): How to handle NaN?
• #107 (closed): Make BaseRunner an abstract base class
• #112 (closed): (LearnerND) add iso-surface plot feature
• #56 (closed): Improve plotting for learners
• #118 (closed): widgets don't show up on adaptive.readthedocs.io
• #91 (closed): Set up documentation
• #62 (closed): AverageLearner math domain error
• #113 (closed): make BalancingLearner work with the live_plot
• #111 (closed): (LearnerND) flat simplices are sometimes added on the surface of the triangulation
• #103 (closed): (BalancingLearner) make new balancinglearner that looks at the total loss rather than loss improvement
• #110 (closed): LearnerND triangulation incomplete
• #127 (closed): Typo in documentation for adaptive.learner.learner2D.uniform_loss(ip)
• #126 (closed): (Learner1D) improve time complexity
• #104 (closed): Learner1D could in some situations return -inf as loss improvement, which would make balancinglearner never choose to improve
• #128 (closed): (LearnerND) fix plotting of scaled domains
• #78 (closed): (LearnerND) scale y-values

and merged the following Merge Requests:

• !131 (merged): Resolve "(Learner1D) add possibility to use the direct neighbors in the loss"
• !137 (merged): adhere to PEP008 by using absolute imports
• !135 (merged): test all the different loss functions in each test
• !133 (merged): make 'fname' a parameter to 'save' and 'load' only
• !136 (merged): build the Dockerimage used in CI
• !134 (merged): change resolution_loss to a factory function
• !118 (merged): add 'save' and 'load' to the learners and periodic saving to the Runner
• !127 (merged): Resolve "(LearnerND) allow any convex hull as domain"
• !130 (merged): save execution time on futures inside runners
• !111 (merged): Resolve "Make BaseRunner an abstract base class"
• !124 (merged): Resolve "(LearnerND) add iso-surface plot feature"
• !108 (merged): exponentially decay message frequency in live_info
• !129 (merged): add tutorials
• !120 (merged): add documentation
• !125 (merged): update to the latest miniver
• !126 (merged): add check_whitespace
• !123 (merged): add an option to plot a HoloMap with the BalancingLearner
• !122 (merged): implement 'npoints' strategy for the 'BalancingLearner'
• !119 (merged): (learnerND) no more (almost) flat simplices in the triangulation
• !109 (merged): make a BalancingLearner strategy that compares the total loss rather than loss improvement
• !117 (merged): Cache loss and display it in the live_info widget
• !121 (merged): 2D: add loss that minimizes the area of the triangle in 3D
• !139 (merged): Resolve "(Learner1D) improve time complexity"
• !140 (merged): Resolve "(LearnerND) fix plotting of scaled domains"
• !128 (merged): LearnerND scale output values before computing loss

When there is v0.7.0 we can set up the documentation for the latest release and master.